Neewer 55mm Universal Screw Knob Clamp with 50mm Quick Release Plate for Tripod Head Clamp has 3/8" thread stud Its Jaw can be openned from 37mm to 42mm Compatible With any Arca style plate (Really right stuff (RRS), Wimberley, Jobu Design, Arca Swiss, Kirk Enterprises, Markins, etc.) Using M6 flat head screw(included),compatible with virtually any ball head, tripod, Gimbal or monopod, or can be directly mounted onto tripod and monopod. Built-in high-contrast bubble level; designed a release-push to prevent camera unexpected sliding off