Screw-Knob Quick-Release Clamp, 60mm jaws. Traditional screw-knob clamps are tried & true and can deliver slightly greater clamping force than our Lever Release clamps.
Now you can add a screw-knob clamp with captive knob to your Arca-Swiss ballhead. The B2 Pro II has a recessed non-threaded center socket for installation on a head or platform with tapped 1/4"-20 socket or tapped metric 6 socket. Clamp features captive knob and safety stop relief grooves. It can mount on RRS ballheads, current model Arca-Swiss ballheads, and Manfrotto 468, 488RCO, 469, 468RC2, & 469RC heads.
B2 Pro II is 60mm (2.36") long with one recessed non-threaded center socket, safety stop relief grooves, captive knob, spirit level, and centering index marks, 4.3oz/124g
Metric 6 or 1/4"-20? Clamp comes with one flat head screw. Determine which one you need before purchase. Really Right Stuff ballheads use the 1/4"-20 screw, all other heads use metric 6 screws.