Small version of the RAM Tough-Claw base is designed to quickly clamp to round, square, and odd-shaped rails and bars ranging from .625"" to 1.5"" in outer diameter; rubber pads provide stable gripping and protection of mounting surface. Spring-loaded 'X' design with rubber caps sports great holding power without hiding your phone; includes optional device tether for peace of mind during rugged use. Made of high-strength composite and stainless steel hardware for durability and reliability in the most demanding environments. Holder dimensions: Width Range: 1.875"" - 3.25""; Depth Range: 0.875"" max. Rail/Tube Clamp Range: 0.625"" - 1.5"" Diameter; Flat Surface Clamp Range: 0"" - 1.14"". Backed by a lifetime warranty