The TRBU75 works with any 75mm Bowl adapter. Designed to level a tripod faster and easier than adjusting tripod legs separately. Easily level any tripod with 75mm bowl. This leveling Half Ball (Bowl) adapter is made out of strong yet lightweight aluminum, to keep weight at minimum. To tighten simply rotate the knob, to loosen reverse. Note: Requires bowl adapter to work with PMG Pro-Stix series tripods (TRB3475 - 34 Series) or (TRB75 - 42 Series) For mounting standard base photo and video heads 3/8-16 top mounting screw with non-flexible base for stability 75mm half ball Works with 75mm Bowl System CNC-Machined T6061 Aluminum Construction Satin black anodized for abrasion and corrosion resistance Made in USA