ITEM NAME:1" Underwater Ball Clamp Adapter for Light Flash Photo Video 1/4" Device Description: 1" Metal Light Ball Arm Adapter Underwater Part of System Monitor Mount 1/4"-20 Universal for GoPro Sony Nikon Canon Cameras. Wide Applicationï ¼Å¡mount flash light, on-camera field monitor to sliders, tripods more photography device with 1/4" hole. Compatible with 1" ball clamps and other accessories. Connect two ball adapters with a clamp to make an arm. Part of the ball arm mounting system. Specification: Materialï ¼Å¡Metal Sizeï ¼Å¡7.37*7.37*2.54 cm/2.9*1*1 inch Ball Adapter Length: 6.9cm/2.5 inch Stud size: 1/4"-20 Package Includes: 1x Ball Adapter(1/4"-20 to 1").Connect two ball adapters with a clamp to make an arm. 1x Ball Adapter(1/4"-20 to 1"). Part of the ball arm mounting system.