Arkon's XLRMCPM RoadVise XL Robust Clamp Phone or Tablet 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. The mount's spring-loaded holder fits devices (even those with skins and ruggedized cases) up to 5'' wide. The mount is compatible with Apple iPhone XS Max, iPhone XS, iPhone XR, iPhone X, iPhone 8 Plus, iPhone 7 Plus, Samsung Galaxy Note 9 and Note 8, Galaxy S10, S9, and S8, LG G6, G6+, G5, and G4, Google Nexus 6, and Nexus 5. This mount is not recommended for phones without a case measuring 2.64 inches wide or less, including iPhone 8 or iPhone 7. The mount also fits midsize (7-8'' screen size) tablets measuring up to 5'' wide, including Galaxy Tab A 8.0, Galaxy Tab E 8.0, Galaxy Tab S 8.4, Galaxy Tab 3 7.0 and 8.0, and Google Nexus 7. This package includes a Robust Clamp Pedestal, the RoadVise XL Phone or Tablet Holder, one 3.75'' Standard Robust Mount Shaft, one 2.75'' Small Robust Shaft, and optional security knob and hardware. This 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.