Premium quality replacement gas lift cylinder made to fit only the Herman Miller Equa I chair - Non-OEM *** Does not fit other chairs Piston stroke / travel height adjustment range of 5" (up & down) Width of piston is 28mm (1.10") ***does not fit any big-box store chairs*** Overall length from end to end when fully extended is 15.6" & 10.6" when fully compressed Attachment hardware included: washers, bearing kit, & retaining clip This premium quality replacement non-OEM gas lift cylinder fits only the Herman Miller Equa I chair - Non-OEM. *** Does not fit other chairs*** Do not purchase if you have not confirmed that you have have an Equa I chair; this will not work. It is not defective; it just only works on one chair. Contact us if you need help figuring out what will work for your chair. If you have a big-box store chair, this will NOT work. A different cylinder is available that fits the Equa II cylinder. Note: This cylinder has no taper and ONLY works on the Herman Miller Equa I chair.