Haoge Universal Quick Release 50mm Clamp + 60mm QR-60II Plate for Camera Tripod Ball Head fit Arca Swiss The 50mm Clamp is an Arca-type compatible clamp with three built-in spirit level for leveling your camera on both the horizontal and vertical planes. There is a 3/8" threaded hole to mount the clamp onto a tripod, and also comes with a 3/8" to 1/4" screw adapter. M6 Screw for mounting the clamp to ballhead or panoramic head. The 60mm plate has a 1/4"-20 screw and two safety stop screws for Cameras, Ballheads, Panorama Head and other Arca-Swiss compatible Quick Release clamps.