MASTERY MART11 Inches-17 Inches Long Office Chair Gas Lift Cylinder Replacement, 5.5" Stroke, Heavy Duty 1000 lbs, Universal Gas Cylinder for Most Office Chair, Class 4 (Not for 1KEA, Black)

The new cylinder was fine, fitted in seconds and works perfectly.The problem is removing the old one. No skill is needed, only a stillson wrench (the bigger, the better) a heavy hammer and brute strength!There are plenty of videos on YouTube, but basically you lay the chair on its side and clamp the stillson to the stem just below where it enters the chair. Then heave-ho, it isn't going to be easy! It doesn't matter which way you turn it, but you must force the tapered joint to release. It will help if whoever fitted it smeared it with grease first. When done, take the base unit outside and hit the base of the old cylinder really hard with a heavy hammer. Again, it's a tight taper fit and really heavy blows will be required. Once done, that's it - just pop the new one in. Don't forget to first replace any gaiters covering the cylinder, or you will be reaching for the stillson again!

Works fine, the height is almost a wee bit too high but it is all good. Super easy to install once the old one is out and there lies the problem.Do not underestimate how difficult it is to take out the old piston. I watched numerous YouTube videos, all claiming to have the secret method, and I tried them without success. The side of the piston where the wheels are mounted - a piece of cake, a stroll through the park, etc. The other side, what a challenge. Finally, a young plumber who was working on our bathroom gave it a try with a massively, long pipe wrench. He just barely got it off and that was with two of us holding onto the chair. At the end of the day, it's cheaper to repair than to buy a new chair. But, the next office chair I buy will be fixed in height with no piston.

Great replacement cylinder for office chair.. considerably cheaper than buying a new chair ......BUT... extracting the old cylinder was not "easy".. yes its a "simple" press fit but it was impossible to twist / pull it out .. a lump hammer and steel drift required to do the job. Once out .. it is easy to fit the new cylinder

Easy to fit

amazing gas lift, if you want to enjoy silence and pleasant use, then this is your option, but I realized this after two days, let's see how it will show itself over the next month

So I watched a video of a young woman giving a gentle twist and tap and out comes the old gas lift cylinder and all in 30 seconds. The reality is the cylinders can be devilishly difficult to remove so be prepared for using a bit of brute force and a lot of swearing. After eventually removing the top end from the chair with a pipe wrench and lashings of wd40. It took several hefty blows with a lump hammer to remove the casters end. That said the replacement seems of good quality and will add a few more years of use to a perfectly serviceable chair.

Good price with excellent delivery service.

I bought this replacement gas cylinder after my original one began to fail before xmas. After a lot of hammering and applying some WD-40, I was eventually able to remove the old cylinder from my chair then quickly attach the new cylinder.I decided to go for the extra long cylinder being a tall person, thinking the extra inches would allow me to sit at an more optimal level as opposed to the standard length of cylinder which felt too low, even at its highest point.. and my thinking was correct, also the cylinder supports up to 250kg which is more than ideal for me, being on the larger size (6ft 3 in - 200kg+).So far. the cylinder feels sturdy and solid and would recommend to anyone in the same position as myself