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 16mm to 38mm OD. Ideal for mounting tablets, action cameras, smartphones, rod holders for rod storage plus electric motor shaft support when traveling and much more in a wide variety of applications. Perfectly suited for mounting on the yoke of an aircraft, handlebars and seat posts of bicycles, kayak rails, roll bars and much more. Clamping Range (Rail/Tube Surfaces):16mm to 38mm OD Clamping Range (Flat Surfaces): 0mm to 29mm.