Unior Pro shop clampQuick release system enables the mechanic to close the jaws by hand, at which point clamp already grips the seat post or frame with sufficient force to hold the bicycle in place. Rotate the handle and additional tension is applied to ensure firm grip Clamp can grip tubes of any shape with diameter 22 to 60mm Quick release button: used to release the jaws after initial tension release with the rotating handle Height of the jaws is 70mm, works with