If your chair is unable to adjust up and down then you may be in need of a new Hydraulic Lift Cylinder. FRNIAMC drafting stool chair gas lift cylinders are more heavy duty than standard chair gas lift cylinders. It is universal size is compatible with damaged or worn out hydraulic lifts on office drafting chairs, task chairs, executive chairs.it may not fit all. Please remove cylinder with care and measure to be sure. Minimal differences in measurements should not alter performance of lift when installed in chair.