Haoge 64mm Screw Knob Clamp Adapter with 70mm QR Quick Release Plate for Camera Tripod Ballhead Monopod Ball Head Fit Arca Swiss Haoge CP-64 Quick Release Clamp + QR-70II Quick Release Plate for Tripod Monopod Panoramic Ball Head Compatible Arca-Swiss The Haoge 64mm (2.52") Discal Clamp is a Arca Swiss compatible screw knob clamp. It will accept any standard Arca-Swiss quick release plate. There is a 3/8" threaded hole at the center for mount the clamp onto a tripod or monopod. The 70mm slide-in quick release plate has a 1/4"-20 connecting screw and two safety stop screws.