Bessey STE-LH Multi-Function/Laser Fixture – Accessory with 1/4″ thread for holding a laser, camera etc. 

Can be used without tools on round (0-45 mm) and angular (0-55 mm) support parts such as ceiling and assembly supports, profiles, ladders. L-shaped rotating fixture with 2 rotation axes: 360° next to fixing clamp, 180° at threaded connection.