Studio-98 Six ( 6 ) Metal C Clamp (or G Clamp) Grips with 5/8 Inch Stud Spigot and 1/4" Thread for Photography Studio Light Support. Monolight Flash Mount or Light Stand Comes with six ( 6 ) C-clamps (or called G-clamp). Made of Heavy duty steel. For attaching studio gears to poles / bars or flat surfaces such as board & table. Each clamp is fitted with a standard sized 5/8" metal spigot with a 1/4"-20 thread. It will hold loads of 5-10kg kg. Jaws open 3.5 cm / 1.4" (edges) and 4.0 cm (center) Jaws are approx. 4.0 cm wide (1.6 inch ) with rubber pads on clamp and screw to protect item and provide better grip.