The RAM-D-202U consists of a 2.25" diameter rubber ball connected at right angles to a 3.68" diameter round plate. The plate has pre-drilled holes in the base plate including two holes at 180 degrees and three holes at 120 degrees. Material: Powder Coated Marine Grade Aluminum Ball Size: 2.25" Rubber Ball "D" Size Product : RAM MOUNT 3.68" DIAMETER BASE W/ 2.25" D SIZE BALL Manufacturer : RAM MOUNT Manufacturer Part No : RAM-D-202U UPC : 793442202025