The CAMVATE Single 15mm Rod Clamp with 1/4"-20 Thread & Screw, with a red ratcheting knob, features two 1/4"-20 threaded holes and includes a 1/4"-20 conversion screw that can be installed into one of the threaded holes. Depending on the accessory you want to mount, you can choose to make use of either hole or the screw. The ratcheting knob is spring-loaded so you can adjust it not to interfere with other gear on your rig.
UPC: 619125204738