The RAM large 4" rubber suction base consists of the 1" dia. ball and socket system with RAM Plate and mounting hardware to connect to the Magellan Roadmate cradle. The cradle is included with the purchase of the Roadmate, or you can purchase a new cradle. Part number reflects product packaged in clear clam shell for store shelf display. For additional specifications, see components and drawings tabs.Black Powder Coat1 Inch Rubber BallPowder Coated Marine Grade Aluminum