The RAM® Double Ball Mount with Backing Plate & Diamond Plate (RAM-B-138U-225B2) consists of a double socket arm, one 2.5" diameter round base, one 2.43" x 1.31" diamond base, one 2.10" x 2.60" backing plate, and mounting hardware. Each base features the universal AMPS hole pattern, making them compatible with all RAM® device holders. The mount is designed with a 1" diameter rubber ball and socket system that features adjustment points at both ends of the double socket arm, allowing for near-infinite adjustability for ideal viewing angles.