The RAP-B-404-GOP1U consists of the medium Tough-Claw base, double socket arm and and 1" diameter ball with custom GoPro Hero adapter. The RAM Tough-Claw is the perfect mounting base for quick and easy tool-less installation and removal on round, square, odd shaped rails and bars. The Tough-Claw can be clamped on rails from 1" - 1.875" outer diameter. The mount is designed with a RAM 1" diameter patented rubber ball and socket system that has adjustment points at both ends of the double socket arm; this allowing for almost infinite adjustment and perfect viewing angles. The GoPro Hero adapter attaches directly to the under-side of the camera, replacing the factory mounting bracket. Clamping Range (Rail/Tube Surfaces): 1" to 1.875" Clamping Range (Flat Surfaces): 0" to 1.6"