38mm Screw-Knob Clamp | B2-FAB

Screw-knob Clamp, 38mm jaws 
Why should you invest in a quick-release system? Because screwing your camera or lens onto a platform with standard 1/4"-20 screw is tedious and insecure. Not only is it a hassle to screw your gear onto that platform, but once installed the camera or lens is free to rotate; there's nothing to prevent it from coming loose. Why invest your money in a tripod and tripod head only to compromise your shots with an insecure connection between camera and head? Instead, adopt the Really Right Stuff quick-release system. 
The Really Right Stuff quick-release system is based on the Arca-Swiss standard and has two parts: a quick-release clamp and a quick-release plate. You always need both pieces of the system. The clamp will stay on your tripod head/accessory all the time, and the plate will stay on your camera all the time. You will need to purchase a separate quick-release plate for each camera or collared, telephoto lens that you want to mount in the quick-release clamp on your tripod head. 
Clamp jaws open and close in one of two ways: by twisting a knurled knob on our tried & true screw-knob clamps; or by flipping a single lever on our innovative, patented lever-release clamps. Traditional screw-knob clamps are tried & true and can deliver slightly greater clamping force than our Lever Release clamps. 
Mini-clamp with 1/4"-20 threaded socket and anti-twist tabs, 38mm jaws. The B2-FAB mini-clamp has one 1/4"-20 threaded socket for screwing onto a 1/4"-20 threaded post or stud. "