This ULTRALIGHT AC-CSB CLAMP FOR BUOYANCY ARMS is used to connect the Ultralight 2" buoyancy arms to your underwater camera housing rig. This clamp measures 2" between the centers of the ball recesses and is built around a 1/4"-20 coarse threaded bolt. The black anodized T-knob makes tightening and loosening the clamp easy, and it can be useful to the cinema industry for color-coding camera rigs.