RAM EZ-Roll'r Drill-Down Mount with Plate for Garmin nuvi 2500 Series (RAM-B-138-GA57-225BU) (sku 54239)The RAM B 138 GA57 225BU consists of a double socket arm, 2. 5" diameter round base with the universal AMPS hole pattern, diamond adapter base, custom high strength composite cradle and steel backer plate for the listed compatible Garmin nuvi 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 flat surface nuvi mount to