The Pro Mechanic/Pro Mechanic HD Workstand Tri-Knob is a spare for the oversized, die-cast metal rear knob that is used to fix the position of the 360° rotating seat post clamp of the Pro Mechanic and Pro Mechanic HD workstands.
Compatible only with those stands, and not with older stands such as the Ultimate and Pro-Elite, this tri-knob comes with a red dust cap and is strongly built to help bear the weight of heavy mountain and E-Bikes.