RAM 2-7/16″ X 1-5/16″ Base w/BallPart #: RAM-238UThe powder coated marine grade aluminum base contains a 1.5″ diameter rubber ball connected at right angles to a 1.25″ x 2.5″ inch diamond plate. The base has two holes 1.912″ from center to center, positioned at both ends of the diamond base. Material: Powder Coated Marine Grade Aluminum Ball Size: 1.5″ Rubber Ball Size Note: The “U” in the part number reflects product packaged in poly bag.