The 360-degree rotating clamp uses a spinner knob closure that can accommodate up to 1.9" (4.8cm) and support 35lbs (16kg) working weight. This Spinner Knob replacement head comes with all necessary hardware for installing onto an existing Feedback Sports Repair Stand and some older Ultimate tri-pods (verify that your existing tri-pod has a 1-1/2" tube and the necessary 1/2" pre-drilled hole).