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 1.14" in outer diameter; rubber pads provide stable gripping and protection of mounting surface Spring-loaded 'X' design for large phones 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 Phone Holder Dimensions: Width Range: 1.75" - 4.5"; Depth Range: 0.875" Max Rail/Tube Clamp Range: 0.625" - 1.14" Diameter; Flat Surface Clamp Range: 0" - 1.14" Backed by a lifetime warranty