













🪑 Upgrade your throne, rule your workspace!
This 14-22 inch extra-long gas lift cylinder offers an 8-inch adjustable stroke, crafted from premium Class 4 steel to support up to 1000 lbs. Designed for universal compatibility with most drafting chairs and bar stools, it ensures smooth height adjustment and 360-degree rotation while eliminating sinking issues. Easy to install and built for heavy-duty use, it’s the ultimate upgrade for professionals seeking ergonomic comfort and lasting reliability.






| ASIN | B099RMKP99 |
| Age Range (Description) | Adult |
| Arm Style | Armless |
| Assembly Instructions Description | DIY |
| Back Style | Mid Back |
| Best Sellers Rank | #5,984 in Office Products ( See Top 100 in Office Products ) #133 in Office Furniture Accessories |
| Brand | MASTERY MART |
| Color | Matte Black |
| Customer Reviews | 4.5 4.5 out of 5 stars (2,790) |
| Date First Available | October 12, 2021 |
| Fill Material | Foam |
| Form Factor | Tower |
| Included Components | No components included |
| Indoor/Outdoor Usage | Indoor |
| Is Customizable | No |
| Is Discontinued By Manufacturer | No |
| Is Foldable | No |
| Item Weight | 1.76 pounds |
| Item model number | GAS-AD8 |
| Leg Style | Straight Leg |
| Manufacturer | Mastery Mart Co., Limited |
| Pattern | Solid |
| Product Care Instructions | Wipe Clean |
| Product Dimensions | 13.9"D x 2"W x 2"H |
| Reclining Position Count | 1 |
| Room Type | Office |
| Shape | Cylindrical |
| Size | 8'' Travel Length |
| Special Feature | Durable, Easy to Replace and Install, Heave Duty, Quality Guaranteed, Universal Fit |
| Style | Solid |
| Unit Count | 1 Count |
Y**H
Perfect Fit and Works Exactly as Expected
Great replacement cylinder! The size was spot-on, installation was straightforward, and it brought my chair right back to the height and stability it originally had. Smooth lift, solid feel, and no sinking issues at all. Exactly what I needed highly recommend if you’re repairing or upgrading an office chair.
Y**E
Hallelujah the chair is fixed!
This worked perfectly to fix our computer chair and our manners! It was embarrassing to slowly sink uncontrollably in our computer chair every time we sat in it - especially in front of guests. It was easy to assemble and the chair feels very sturdy now. I love not sinking anymore! It really is the little things in life that make me feel happy, this chair part helped a lot!
J**L
Steel Case Leap V2
Works great with my Steel Case Leap V2. The previous strut never worked all that great but this new one is soft and doesnt drop down. I went with a taller one to fit my desk heigh of 36" and its a perfect match with the 11-17 inch.
V**S
Game changer!
Perfect replacement for a high top office chair!! It’s wonderful to have a normal height chair!!
J**E
No Instructions on how to remove old cylinder
Removing the old cylinder necessitates the use of a hammer, wrench, lubricant, and potentially a vice to secure the chair legs during extraction. Significant force is required for removal. No instructions were included in the cylinder packaging, making it necessary to consult a YouTube video for guidance. The device appears to be functioning properly following installation.
A**E
Helped Avoid Cost of A New Chair - FIXED!
My office chair turned out to be a disappointment after the backrest wouldn't stay up due to the plastic turn knob not staying tight no matter what I did. Then when my chair started to lose its lift on a regular basis I thought I would have to buy a new chair. I would sit down at my desk and realize I was sitting at the same height as a child does. Sad, because my previous chair lasted about 18 years. When I discovered this gas lift cylinder replacement I thought it would be worth a try to mitigate the expense of a new chair. I took the measurements from my chair in regards to how far it lifted from where it bottomed out to where it extended to and determined the 4.5" stroke height was the one I needed. I didn't know what "stroke height" was but I figured it out. Once I received it, I needed to remove the old cylinder, which was the HARDEST part of the task. I removed one end with a few hardy smacks with a hammer as illustrated on YouTube. Additionally, after unsuccessfully removing the other end with a pipe wrench as instructed, I had to disassemble the chair's mechanism to dislodge the end of it that was completely stuck in the chair pan. It took some creativity to get it done, but after about an hour of trial and error I got the old one out. At that point installing this new cylinder was SUPER easy. It fit exactly like it was supposed to. The chair is fixed! And I even fixed the other problem of the backrest not staying in position after seeing a fix on YouTube while looking at videos for installing a new chair cylinder. Now my chair is actually better than it was to begin with. The chair is stable and raises and lowers well. I look forward to an uplifting experience from this point forward (pun intended). I would recommend this fix to anyone who wants to save $150-$200+ on a new chair.
H**T
Great For Converting An Office Chair Into a Counter Height Stool. Will Make The Chair Taller.
I wanted to turn a really nice office chair into a counter stool for my mother. I realized that I needed to convert the wheels to stationary chair guides, and to buy a new gas cylinder that increased the max height of the chair. I actually did some measurements prior to purchasing this. Most office chairs have a maximum height of around 21-22 inches. My chair had a max height of 23.5 inches, but I still needed higher. And I later learned that I would need to account for the "plushiness" of the cushion, compared to a firmer bar stool type chair, as the cushion would sink in an inch after you were sitting in it. I was weary about how long these things last, so I tried to buy the exact size where the minimum setting was high enough to not require it to be lifted at all. So I originally bought the 8 inch lift gas cylinder. At it's minimum height, this made the chair like 27 inches high, which was too high for my needs. I ended up exchanging the 8 inch one for this 4 inch gas lift that was slightly too short, but only required a tiny bit of lift. And for the price these cost, I'm no longer worried about them not lasting for years. I can just buy another one. Installation was easy, because it was a relatively new chair. I recommend you take the wheel base off first. So place your chair probably head down, ideally on some carpet, fully exposing all wheels in the air. Then get a rubber mallet and hit against the gas lift bottom while pulling on the wheel base, and eventually the base will come off. Then get a pipe wrench or some kind of wrench with a wide enough opening, and turn it the lift cylinder to the left. Mine came off relatively easily. The whole process probably took less than 5 minutes which surprised me cuz some people say it takes like an hour of banging. My original chair piston was not broken, so I wanted to preserve it the best I could. Some say you can protect it from scratches if you put like a rag in between, but in my opinion, that's not feasible because it'll just cause the wrench to spin. I removed the old piston the best I could, but there are pipe wrench marks on it. I wanted to keep it because not only is it still good, but if I ever wanted to turn it back into a regular chair I could. Only had it about a couple of weeks, but so far so good. You're apparently suppose to go up and down on the cylinder every week or so to keep the piston lubed, but I've never done that, and most people probably don't once they find the ideal height. But that's what you're suppose to do for maintenance. I'll reiterate that I do believe this may make your chair taller than it was before on it's lowest setting, and has the range to make it much taller (drafting chair height) if desired. I've never had an issue with these before, because I always sit at the lowest setting which is around 17 inches on most chairs.
G**S
Save your coins
It was a bunch of crap as soon as I sat on it the second time down I went this mess doesn't hold weight this is the second one I bought different companies tho. I feel I have to just by a hold new seat i don't trust these companies that make these particular products, gbe first one i bought from a different company was used or replaced by someone else however I don't think I'll be doing this again, I'm not even gonna bother sending it back so customers beware all I can say it doesn't hold weight I'm 200lb plus. The one I received didn't even extend to full height my grandson daughter a little over 100lb sat down. And down she went like a broken elevator crashing free falling
C**E
Es funcional, es lo que requeria
A**R
Fits perfectly!
B**6
Item arrived on time and as described. The fit is very well and it works very well as a replacement for the original hydraulic piston that had worn out.
S**N
Very well made. Super sturdy.
T**S
fonctionne très bien, remplacement de mon ancien défectueux,facile a changer mais avec le matériel adéquat et un peu d'huiles de coude pour le reste conforme a met attente. je recommande.
Trustpilot
2 weeks ago
2 days ago