The phot r double c clamp has many different applications within the studio it can be clamped onto lighting stands tripods auto poles and shooting tables with a pole diameter of up to 4cm it is essentially two c clamps joined back to back at a 90deg angle allowing you to build custom lighting rigs it is a versatile piece of kit that no studio should be without can be clamped onto most light stands auto poles and tripods up to 4cm in diameter rubber caps on the clamp to protect you