Pneumatic cylinder cartridge strut replacement for standard office chair pneumatic cylinders. This cartridge has a 5\" stroke / travel. Typically used on Task chairs or if you need an extra inch or 2 on any chair. Main body is 1.1\" (28mm) diameter and is 10\" long (not counting solid rod) The tapered end that goes into the seat plate / mechanism has a standard 17-4 taper. Once installed properly, this cylinder will give you a total of 5\" height travel / stroke from lowest to highest setting. The steel used is heat treated making it stronger