The RAM 4″ rubber suction base mount consists of the 1″ dia. ball and socket system with RAM Plastic Cradle for the Garmin GPS II, II Plus, III, III Plus, III Pilot and V. The rubber suction cup base has a 1.0″ diameter rubber ball connected at right angles. The suction cup is designed to hold on any smooth non-porous surface, but for best result, mount the suction cup on a glass surface. Part number reflects product packaged in clear clam shell for store shelf display. For additional specifications, see components and drawings tabs.