The Avenger C150 Swivelling "C" Clamp is an extremely robust Gravity Cast clamp that is designed to clamp onto truss, pipe grids, or round tubes. It is rated to hold from 22lbs - 165.3lbs (10kg - 75kg) (Up to 22lbs [10kg] on the 5/8" [16mm} retractable spigot and up to 165.3lbs [75kg] on the Junior 1-1/8"[28mm] receiver.). The clamping range on this clamp is 1.1" - 3.1" (28mm - 78mm). The added swiveling feature allows for easy aiming of any light. The clamp includes a safety cable for the junior pin and an additional thumb screw to securely lock the pin when needed.