The RAM-B-174-GA32U consists of a double socket arm, hardware for mounting to both brake/clutch reservoirs and rails that are 0.5" to 1.25" in diameter, diamond adapter base and custom high strength composite cradle for the Garmin nuvi 500 series. Designed into the mount is a 1" diameter patented rubber ball and socket system with adjustment points at the base and cradle. With a twist of the arm knob, you can move the motorcycle nuvi mount to your optimum viewing position. The mounting hardware for brake/clutch reservoirs include both standard and metric mounting bolts. This mount is designed to hold the following devices: Garmin nuvi 220, Garmin nuvi 500, Garmin nuvi 510, Garmin nuvi 550, Garmin zumo 220. Included with Purchase: (1 qty) High strength composite cradle (1 qty) Base/ball adaptor (attaches directly to cradle) (1 qty) Standard size double socket arm (1 qty) Mounting base (mounts to either brake/clutch reservoir or rail/handlebar) Hardware for mounting to either brake/clutch reservoir or rail/handlebar.