The RAM-B-121-UN9U consists of a yoke clamp base, double socket arm, round adapter base and universal X-Grip^® clamping cradle for 22.86cm (9") -27.94cm (11") tablets. The RAM yoke clamp mount will fit rails from 1.59cm (0.625") to a maximum of 3.18cm (1.25") . The 2.54cm (1") rubber ball is at a right angle to the plane of the mount; when connected to a rail, the ball sits parallel to the rail. 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 X-Grip^® clamping cradle consists of a composite spring loaded cradle, expandable grip arms and additional bottom support keeper. Included are extra easy access grip knobs, located on the back of the cradle for quick release of your tablet. The X-Grip^® clamping cradle expands and contracts for perfect fit of most 22.86cm (9") -27.94cm (11") tablets with or without sleeves, as well as some smaller tablets. Please verify dimensions of your tablet below for compatibility with the X-Grip^®.