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Items weighing 149 lb or less ship by ground parcel rather than freight.
Bars, handles and straps shown in photos are not always included. Check the description, or add attachments to your order.
Receive by Dec 10estimated, may change
Remanufactured
Nautilus Nitro Plus Lower Back
$1,495.00
$1,196.00
Save $299.00
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at checkout
4.8
ConditionRemanufactured
Availability
Out of Stock
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See similar machines in stock →Parts & Labor, Fully Rebuilt
Remanufactured to full mechanical spec, covered from the day it lands. Wear items are not covered.
Bars, handles and straps shown in photos are not always included. Check the description, or add attachments to your order.
Shipping calculator
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Machine overview
Condition: Remanufactured
Warranty: 1 Year Parts & Labor (Extended Available)
Returns: 30-Day Returns & Exchanges
Shipping: Driveway Delivery, or Inside Delivery & Assembly
Receive by: Dec 10
How It Ships: Fully Assembled
Delivery options
How delivery works
Your item’s shipping method and price are confirmed in the shipping calculator and at checkout. Here is what each delivery path means.
Driveway freight delivery
Your equipment is palletized and protected. The freight carrier schedules delivery, then uses a liftgate to lower it to your curb or driveway. Moving it inside and unpacking it are up to you.
Inside delivery & assembly
When selected and available for your address, the delivery team brings the equipment into the room, assembles and tests it, then removes the packaging.
Full truckload
For commercial builds and multi-pallet orders, a dedicated trailer keeps the full order together in one delivery. We confirm the unloading plan before the truck ships.
Size: 56" × 38" × 54" tall
Weight Stack: 200 lb
What Remanufactured Means
Every remanufactured machine is fully disassembled, deep cleaned, repaired or re-parted to factory spec, then tested under load before it ships. Backed by one year parts and labor, with extended coverage available.
Warranty Coverage
New and remanufactured equipment are both covered for one year, parts and labor, backed by us. Extended protection is available on either through BAG Care+. Used equipment is sold as-is with no warranty coverage, and is described honestly before you buy. We service nationwide - every ZIP code in the country - so coverage travels with the machine.
30-Day Returns & Exchanges
Change your mind within 30 days of delivery and you can return the machine or exchange it for a different size, color or configuration.
Return shipping is the customer's responsibility and a 15% restocking fee applies to preference returns and exchanges. Freight items must go back packaged to the same standard they arrived in. We will tell you exactly what that means before anything is collected.
Anything that arrives damaged or fails under warranty is handled separately and carries no restocking fee. Full terms are in our Returns, Exchange & Refund Policy.
Add before it ships
Before the freight bookingCoverage and accessories have to go on the same booking as the machine. Add them here and they travel together.
Extended warrantyRecommendedEvery machine includes 1 year parts and labor.
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Customer reviews
Real Gyms. Real People.
See why gym owners and home gym builders trust Build A Gym with their gyms.
4.8
★★★★★
280 reviews on Google
Write a review
-
2 days ago
★★★★★
CTX/ Build-a-Gym absolutely CRUSHED IT! I had been struggling with numerous manufacturers trying to get a seated leg press/extension that’d ship to Alaska. When I found CTX, they went above and beyond to get my Fractal packaged and shipped with no hassle. I HIGHLY recommend these folks to anyone looking for solid commercial quality equipment for their home.
Read on Google
Thank you guys!!! -
6 days ago
★★★★★
I own a gym in Northern California and have ordered from this company many times, they are quality! Great deals, great communication, great products!
Read on Google -
2 weeks ago
★★★★★
Nicole was extremely helpful, communication was tops, takes care of business. Thank you!
Read on Google -
4 weeks ago
★★★★★
Equipment is awesome. Delivered and setup in the garage. Will be going back for more
Read on Google -
4 weeks ago
★★★★★
By far the best equipment I’ve had and very reliable for my home and it’s also for a commercial gym also I have The Zaia
Read on Google -
a month ago
★★★★★
Had some issues with the assembly process. Dillan was quick to reach out and set up a video call for assistance. He provided follow ups to ensure everything was squared away. Great customer service!
Read on Google -
a month ago
★★★★★
Great communication, products, and I'm very happy with what I purchased from them. I will be back!
Read on Google -
2 months ago
★★★★★
Just want to say thank you to the team at CTX!! Not only was shipping fast and efficient, but customer service was outstanding!! Any question that was needed to be answered was meet with a quick response. Thank you again!!
Read on Google -
2 months ago
★★★★★
Dillon was very helpful, patient with answering all my questions, very knowledgeable. He insured I had all the necessary answers before I made my purchase. Thanks Dillon, great customer service!
Read on Google -
3 months ago
★★★★★
I was thinking about getting Ozempic, but I’m not in the mood to go blind yet. So I decided I’d do it the old fashioned way and called CTX.
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3 months ago
★★★★★
CTX Built is a great company to work with. Excellent communication and customer service. Their team was easy to work with and extremely helpful. Would do more business with them and I plan to.
Read on Google -
3 months ago
★★★★★
CTX stands by their products. I recently purchased a Precor elliptical from them & it arrived with a mechanical flaw. They coordinated with a technician to get my product fixed like new. They accomplished this despite the fact that my home was two states away. Special thank you to Nichole for staying accessible and attentive throughout the process!
Read on Google -
3 months ago
★★★★★
Great product and awesome leadership. Equipment was straight forward to build and team is always responsive when needing information or any help whatsoever. So glad I found them for outfitting my gym, best decision I have ever made for my business!
Read on Google -
3 months ago
★★★★★
Absolutely best in business! Not only is Dillon just genuinely a great human being, he’s real and honest. Loved everything I’ve gotten from him and the team. I’m about 10-15 pieces in deep with him and not stopping anytime soon! Absolutely recommend hitting these guys up for home/commercial equipment. New or refurbished!
Read on Google -
5 months ago
★★★★★
Excellent selection of products with a large selection, consultants will help you decide
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5 months ago
★★★★★
Dillion was great to work with!! Super friendly, quick turn around time, and great at communicating! The guys who delivered it Robb and JJ were also amazing. They came prepared and were very fast and efficient. They offered to help us move around other equipment to ensure we loved our gym! Super nice people and an amazing company! I would highly recommend working with them. Oh and the equipment itself is high quality and looks great in our home gym!
Read on Google
Rebuilt in our Jarrell, TX shop
What remanufactured means here
Every machine we sell as remanufactured goes through the same process, whatever the brand or the price. Not a wipe-down and a price tag.
-
Inspected and stripped down
Assessed frame to console, then taken apart and checked part by part. Nothing gets judged from the outside.
-
Moving parts rebuilt or replaced
Every moving and touched component, from belts and cables to bearings, bushings and grips, is evaluated and rebuilt or replaced, then the machine gets a full cosmetic restoration.
-
Refinished and rebuilt to spec
Electronics bench-tested, frames and welds checked, panels refinished, then reassembled to the manufacturer's specification.
-
Tested under load
A full operational cycle under load before it ships. Anything that fails the final check goes back through service, not onto a truck.
Get an email when new machines land
Good units go fast. We'll email you when new machines land - nothing else.
Shop photo
Real photo, similar machine
Same shop, same process
Every machine we sell goes through the same shop as this Cybex VR1 Back Extension, photographed recently in Texas.
- Model shown
- Cybex VR1 Back Extension
- Stage
- On the bench
- Photographed
- Nov 9, 2026
- Where
- Our shop in Texas
- Headed to
- Rebuilt by
Rob L.
- Inspected frame to console, then fully disassembled
- Every moving and touched component rebuilt or replaced
- Full cosmetic restoration
- Tested under load before it ships
This photo shows a Cybex VR1 Back Extension, not this exact model. Every machine we sell goes through the same process.
See the full remanufacturing processProduct details
Commercial-grade equipment, inspected and supported by warranty.
Quick answer: The Nautilus Nitro Plus Lower Back is a remanufactured commercial selectorized lumbar extension machine. It isolates the erector spinae in a seated extension with an angled back pad and lumbar support, an adjustable range limiter that caps the arc at a comfortable range, and a gas-assisted seat. The frame measures 56 in. by 38 in. and weighs 572 lb.
The Nautilus Nitro Plus Lower Back machine delivers seated lumbar extension with angled back pad and lumbar support for spinal alignment, adjustable range limiter for customized motion arc, smooth resistance system, gas-assisted seat adjustment, and commercial-grade Nautilus Nitro Plus construction - 572 lb frame, 56"×38" footprint. The lower back extension machine is the only dedicated lumbar isolation machine in the catalog - it targets the erector spinae group through a seated extension movement that no other selectorized machine replicates. The erector spinae are the primary muscles that hold the spine in extension against gravity during standing, walking, and most lifting activities - weakness in the lumbar erectors is the most common structural contributor to chronic lower back pain. Strengthening them in a controlled, supported range produces direct benefit for posture, lumbar stability, and injury prevention across both rehabilitation and performance populations. The seated lumbar extension machine is the appropriate tool for this because it isolates the erector spinae without requiring the hamstrings, glutes, or hip extensors to assist - which is what happens in standing deadlifts or back hyperextension on a GHD. The angled back pad and lumbar support position the spine at the correct starting angle for the extension movement, which ensures the force is directed through the erector spinae along their fiber orientation rather than producing shear force at the lumbar vertebrae. The adjustable range limiter is the safety specification that makes this machine appropriate for users with injury history or limited lumbar range: the limiter caps the extension arc at the user's comfortable range, preventing the movement from extending into the positions where disc or facet joint loading becomes counterproductive. Gas-assisted seat adjustment allows positioning without effort - relevant for users with pre-existing lower back pain for whom bending to adjust a mechanical seat would be contraindicated.
Smooth resistance system for joint-friendly lumbar loading. Commercial-grade build quality and upholstery for sustained high-rotation use. 572 lb Nautilus Nitro Plus commercial frame, 56"×38" footprint. Contact us for stack specifications. Remanufactured.
Primary muscles targeted
Erector Spinae Multifidus
Secondary muscles
Gluteus Maximus Quadratus Lumborum
Key features
Angled Back Pad · Adj. Range Limiter - Isolated Lumbar Loading, Controlled Arc
Angled back pad and lumbar support position the spine at the correct starting angle to direct force through the erector spinae along their fiber orientation rather than producing shear at the lumbar vertebrae. Adjustable range limiter caps the extension arc at the user's comfortable range - preventing the movement from extending into positions where disc or facet joint loading becomes counterproductive. The only selectorized machine in the catalog that isolates the lumbar erectors without hip extensor assistance.
Gas-Assisted Seat · Smooth Resistance · 572 lb Nitro Plus Frame
Gas-assisted seat adjustment allows positioning without bending effort - specifically relevant for users with pre-existing lower back pain for whom bending to adjust a mechanical seat would be contraindicated. Smooth resistance system for joint-friendly loading through the lumbar extension arc. 572 lb Nautilus Nitro Plus commercial frame with commercial-grade upholstery for sustained daily high-rotation use.
Specifications
Dimensions (L × W × H)
56" × 38" × 54"
Machine Weight
572 lb
Weight Stack
Contact Us
Angled back pad · Adj. range limiter · Gas-assisted seat · Smooth resistance
Design
Lumbar Ext. · Range Limiter · Gas Seat · 572 lb
Seated lumbar extension · Angled back pad · Lumbar support · Adjustable range limiter · Gas-assisted seat · Smooth resistance · Commercial upholstery · 572 lb · 56"×38" footprint
Buyer questions
What does a lower back machine work?
The erector spinae, the muscles that hold the spine upright. A seated extension trains them without the hamstrings and glutes taking over, as they do in deadlifts or back extensions.
Is a lower back machine safe for beginners?
Yes, when set up correctly. The range limiter keeps the movement inside each user's comfortable range and the lumbar support sets the starting position. Users with a back injury should check with their doctor first.
What warranty comes with this remanufactured machine?
Remanufactured units carry 1-year parts and labor coverage that starts on the delivery date. Register within 30 days of delivery, and see product guarantees for details.
How is it delivered?
It ships as commercial freight to the lower 48 under the delivery level you pick at checkout (curbside or inside delivery and assembly). Review delivery options and the shipping and installation checklist.
Related: back selectorized machines, Nautilus, remanufactured strength.
Rather not build it?
We will assemble it for you
Brought inside to the room you choose
Assembled and set up by our crew
Packaging taken away
Choose Inside Delivery & Assembly as your delivery option at checkout.
How assembly works
1. What are the exact dimensions and footprint of this Nautilus Nitro Plus Lower Back machine?
The machine measures 56 inches front to back, 38 inches wide, and 54 inches high, with a 15 square foot footprint. You may want to allow extra clearance around it for user access and adjustments.
2. What muscles does this machine target and how does it differ from other selectorized machines?
This machine isolates the erector spinae (lower back) muscles through a seated lumbar extension movement. It is the only selectorized machine in the catalog designed specifically for lumbar isolation without involving the hips or hamstrings.
3. What are the main safety and adjustment features?
It features an adjustable range limiter to control the motion arc and a gas-assisted seat adjustment for easy positioning. These features make it suitable for users with back injuries or limited lumbar range.
4. What is the weight and construction quality of this machine?
The machine weighs 625 pounds and is built on a 572 lb commercial-grade Nautilus Nitro Plus frame, designed for high-rotation use and durability.
5. What condition can I expect with this remanufactured machine?
This is a remanufactured unit, fully disassembled, cleaned, repaired, and quality tested in Texas. Cosmetic marks from prior use may remain, but all worn parts are replaced and it is certified for commercial use.
6. What are the delivery options and warranty for this machine?
Delivery is available to all lower 48 states with curbside or inside assembly options at checkout. Remanufactured machines come with a 1-year parts and labor warranty from the delivery date.
30-Day Returns & Exchanges
Buy with confidence. Every Build A Gym order includes a 30-day window to return or exchange, whether you want a different size, color or configuration. Return shipping is the customer's responsibility and a 15% restocking fee applies to preference returns; warranty and damage claims carry no restocking fee. Full details in our Returns, Exchange & Refund Policy.
Quick answer: The Nautilus Nitro Plus Lower Back is a remanufactured commercial selectorized lumbar extension machine. It isolates the erector spinae in a seated extension with an angled back pad and lumbar support, an adjustable range limiter that caps the arc at a comfortable range, and a gas-assisted seat. The frame measures 56 in. by 38 in. and weighs 572 lb.
The Nautilus Nitro Plus Lower Back machine delivers seated lumbar extension with angled back pad and lumbar support for spinal alignment, adjustable range limiter for customized motion arc, smooth resistance system, gas-assisted seat adjustment, and commercial-grade Nautilus Nitro Plus construction - 572 lb frame, 56"×38" footprint. The lower back extension machine is the only dedicated lumbar isolation machine in the catalog - it targets the erector spinae group through a seated extension movement that no other selectorized machine replicates. The erector spinae are the primary muscles that hold the spine in extension against gravity during standing, walking, and most lifting activities - weakness in the lumbar erectors is the most common structural contributor to chronic lower back pain. Strengthening them in a controlled, supported range produces direct benefit for posture, lumbar stability, and injury prevention across both rehabilitation and performance populations. The seated lumbar extension machine is the appropriate tool for this because it isolates the erector spinae without requiring the hamstrings, glutes, or hip extensors to assist - which is what happens in standing deadlifts or back hyperextension on a GHD. The angled back pad and lumbar support position the spine at the correct starting angle for the extension movement, which ensures the force is directed through the erector spinae along their fiber orientation rather than producing shear force at the lumbar vertebrae. The adjustable range limiter is the safety specification that makes this machine appropriate for users with injury history or limited lumbar range: the limiter caps the extension arc at the user's comfortable range, preventing the movement from extending into the positions where disc or facet joint loading becomes counterproductive. Gas-assisted seat adjustment allows positioning without effort - relevant for users with pre-existing lower back pain for whom bending to adjust a mechanical seat would be contraindicated.
Smooth resistance system for joint-friendly lumbar loading. Commercial-grade build quality and upholstery for sustained high-rotation use. 572 lb Nautilus Nitro Plus commercial frame, 56"×38" footprint. Contact us for stack specifications. Remanufactured.
Primary muscles targeted
Erector Spinae Multifidus
Secondary muscles
Gluteus Maximus Quadratus Lumborum
Key features
Angled Back Pad · Adj. Range Limiter - Isolated Lumbar Loading, Controlled Arc
Angled back pad and lumbar support position the spine at the correct starting angle to direct force through the erector spinae along their fiber orientation rather than producing shear at the lumbar vertebrae. Adjustable range limiter caps the extension arc at the user's comfortable range - preventing the movement from extending into positions where disc or facet joint loading becomes counterproductive. The only selectorized machine in the catalog that isolates the lumbar erectors without hip extensor assistance.
Gas-Assisted Seat · Smooth Resistance · 572 lb Nitro Plus Frame
Gas-assisted seat adjustment allows positioning without bending effort - specifically relevant for users with pre-existing lower back pain for whom bending to adjust a mechanical seat would be contraindicated. Smooth resistance system for joint-friendly loading through the lumbar extension arc. 572 lb Nautilus Nitro Plus commercial frame with commercial-grade upholstery for sustained daily high-rotation use.
Specifications
Dimensions (L × W × H)
56" × 38" × 54"
Machine Weight
572 lb
Weight Stack
Contact Us
Angled back pad · Adj. range limiter · Gas-assisted seat · Smooth resistance
Design
Lumbar Ext. · Range Limiter · Gas Seat · 572 lb
Seated lumbar extension · Angled back pad · Lumbar support · Adjustable range limiter · Gas-assisted seat · Smooth resistance · Commercial upholstery · 572 lb · 56"×38" footprint
Buyer questions
What does a lower back machine work?
The erector spinae, the muscles that hold the spine upright. A seated extension trains them without the hamstrings and glutes taking over, as they do in deadlifts or back extensions.
Is a lower back machine safe for beginners?
Yes, when set up correctly. The range limiter keeps the movement inside each user's comfortable range and the lumbar support sets the starting position. Users with a back injury should check with their doctor first.
What warranty comes with this remanufactured machine?
Remanufactured units carry 1-year parts and labor coverage that starts on the delivery date. Register within 30 days of delivery, and see product guarantees for details.
How is it delivered?
It ships as commercial freight to the lower 48 under the delivery level you pick at checkout (curbside or inside delivery and assembly). Review delivery options and the shipping and installation checklist.
Related: back selectorized machines, Nautilus, remanufactured strength.
Rather not build it?
We will assemble it for you
Brought inside to the room you choose
Assembled and set up by our crew
Packaging taken away
Choose Inside Delivery & Assembly as your delivery option at checkout.
How assembly works
1. What are the exact dimensions and footprint of this Nautilus Nitro Plus Lower Back machine?
The machine measures 56 inches front to back, 38 inches wide, and 54 inches high, with a 15 square foot footprint. You may want to allow extra clearance around it for user access and adjustments.
2. What muscles does this machine target and how does it differ from other selectorized machines?
This machine isolates the erector spinae (lower back) muscles through a seated lumbar extension movement. It is the only selectorized machine in the catalog designed specifically for lumbar isolation without involving the hips or hamstrings.
3. What are the main safety and adjustment features?
It features an adjustable range limiter to control the motion arc and a gas-assisted seat adjustment for easy positioning. These features make it suitable for users with back injuries or limited lumbar range.
4. What is the weight and construction quality of this machine?
The machine weighs 625 pounds and is built on a 572 lb commercial-grade Nautilus Nitro Plus frame, designed for high-rotation use and durability.
5. What condition can I expect with this remanufactured machine?
This is a remanufactured unit, fully disassembled, cleaned, repaired, and quality tested in Texas. Cosmetic marks from prior use may remain, but all worn parts are replaced and it is certified for commercial use.
6. What are the delivery options and warranty for this machine?
Delivery is available to all lower 48 states with curbside or inside assembly options at checkout. Remanufactured machines come with a 1-year parts and labor warranty from the delivery date.
30-Day Returns & Exchanges
Buy with confidence. Every Build A Gym order includes a 30-day window to return or exchange, whether you want a different size, color or configuration. Return shipping is the customer's responsibility and a 15% restocking fee applies to preference returns; warranty and damage claims carry no restocking fee. Full details in our Returns, Exchange & Refund Policy.
Save 5%
Complete the room
The machines our install crew puts in the same room as this one - priced as one shipment, delivered in one booking.
$1,495.00
This machine
Bundle total
- Items
- $4,065.00
- Bundle price
- $3,861.75
- Estimated bundle saving
- −$203.25
- Everything arrives by
- Dec 10
One freight booking, one delivery window, one crew. Inside Delivery & Assembly available on the whole bundle.