The RAM-B-347U base consists of a 1" diameter rubber ball connected at right angles to a 2" x 1.7" square base. The base has four pre-drilled holes at each corner, making the universal 1.5 x 1.188 (hole spacing) AMPS hole pattern.
RAM® Double Socket Arm with Round Plate
RAM® Double Socket Arm with Diamond Plate
RAM® Twist-Lock™ Suction Cup Base with Double Socket Arm
RAM® Handlebar U-Bolt Base with Double Socket Arm
RAM® Tough-Claw™ Small Clamp Base with Double Socket Arm