The RAM-B-177-UN8U consists of a glare shield clamp base, double socket arm and universal spring loaded X-Grip cradle for 17.78cm (7") -20.32cm (8") tablets. Simply locate the clamp on any clamping surface up to 12.70 cm (5")/20.32 cm (8") thick and gently snug the nylon thumb screws. The mount is designed with a RAM 2.54cm (1") diameter patented rubber ball and socket system that has adjustment points at both ends of the double socket arm; this allowing for almost infinite adjustment and perfect viewing angles. The spring loaded X-Grip cradle expands and contracts, allowing for a perfect custom fit of your 17.78cm (7") -20.32cm (8") tablet. Included are extra easy access grip knobs, located on the back of the cradle for quick release of your tablet. 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.