The RAM-B-400-C-UN8U consists of the Tough-Claw rail clamp base, LONG length double socket arm and universal spring loaded X-Grip cradle for 17.78cm (7") -20.32cm (8") tablets. The spring loaded X-Grip cradle expands and contracts, allowing for a perfect custom fit of your tablet. Included are easy access grip knobs for quick insertion and release of your handheld device. The Tough-Claw rail clamp base 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 1.59cm (0.625") - 2.90cm (1.14") outer diameter. Perfectly suited for mounting on the yoke of an aircraft, handlebars and seat posts of bicycles, kayak rails, roll bars and much more, the RAM Tough-Claw will soon become another essential RAM component in your collection of mounting options. The X-Grip includes a device tether recommended for outdoor applications. The cradle is compatible with handheld devices that will fit the dimensions listed below. It is important to verify the dimensions of your handheld device with a case/sleeve/skin when determining the overall size.