The SunwayFoto Arca & Manfrotto Compatible Clamp is a CNC machined aluminum clamp that is compatible with both Arca-type plates and Manfrotto 200PL plates. A built-in bulls-eye bubble level helps to level your camera to the horizon and a locking knob opens and closes the clamp to adjust or remove the plate.A numbered scale on the clamp allows for precision positioning of Arca-type plates. Two safety stop grooves allow the use of plates with safety screws, to prevent the plates from accidentally sliding out of the clamp. It has a 3/8"-16 threaded hole to mount the clamp onto a tripod or Ballhead and also comes with a 1/4"-20 bushing adapter.