Arkon's RMCPM2517 Robust Clamp Mount is a highly versatile locking clamp mount with a unique jaw design that has an extra wide clamping range for both flat (including tables, desks, counters, shelves) and tubular (including handlebars, roll bars, wheelchairs, strollers, grocery carts, golf carts) surfaces, including small posts. It is compatible with Arkon's 17mm ball compatible holders and adapters (sold separately). This package includes a Robust Clamp Pedestal, a 25mm to 17mm ball adapter, one 3.75" Standard Robust Mount Shaft, one 2.75"Small Robust Shaft, and optional security knob and hardware. This versatile clamp mount is made of high-strength composite materials with corrosion-resistant stainless steel hardware, and conveniently installs and removes without any tools on flat as well as round, square, or odd shaped bars and rails. Choose from one of either the 3.75" or 2.75"Robust Mount Shafts included to fit your particular mounting environment. Clamp to a table, desk, or other surfaces from .2 inches to 1.75 inches (5mm to 44.5mm) thick. Or, use on a wheelchair, as a microphone stand mount, or on any handlebar or post .25 inches to 2 inches (6.5mm to 51mm) in diameter. The mount installs easily with a turn of the clamp's knob. The clamp is padded in order to provide gripping support and protection to the mounting surface. An optional removable security knob is provided to deter theft. Simply remove the existing knob and tighten the clamp with the security knob. Once tightened, the security knob can be removed to deter theft. Use the Robust Clamp to mount tablets, smartphones, cameras or other devices virtually anywhere.