The 38mm B2-FAB Screw-Knob Clamp from Really Right Stuff is an Arca-type compatible clamp with laser-engraved 1mm scales on each side of 38mm long jaws, so a camera can be aligned within the quick release.
The screw-knob style clamp features a rosette design for secure mounting to compatible ball head and other devices. A legacy tongue-and-groove adapter is available separately. A 1/4"-20 threaded female socket enables the clamp to attach to a monopod or tripod without a quick release. This clamp is constructed using black anodized aluminum.
UPC: 818413023246