The RAP-B-400-238U consists of the small Tough-Claw base, double socket arm and diamond base 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 0.625" - 1.5" outer diameter. The diamond base adapter contains the industry standard universal AMPS hole pattern, which will connect to a large variety of RAM Mount and third party cradles. 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. Clamping Range (Rail/Tube Surfaces): 0.625" to 1.5" Clamping Range (Flat Surfaces): 0" to 1.14"