Gas cylinder replacement for office chairs. This Pneumatic cartridge Spindle Strut Piston with industry standard specifications will work as areplacement of similar size regardless of chair brand. This cartridge Gas Spring has 3.9” Stroke Travel (100mm) and is CLASS 3 with 300n. Main body is 1.1" (28mm) diameter and is 8.75” long. The tapered end that goes into the seat plate / mechanism has a standard 17-4 taper. All hardware including bearing and retaining clip are included.