RAM Yoke Clamp Mount w/Double Socket Arm & Diamond Base AdapterPart #: RAM-B-121-238UConsists of a double socket arm, universal diamond base and yoke clamp base. The hole pattern found on the diamond base will connect to many RAM cradles, as well as third party cradles including mounts with the industry standard AMPS hole pattern. The clamp base will accommodate rails in diameter from 0.625" to 1.25". The 1" rubber ball is at a right angle to the plane of the mount so when connected to a rail, the ball sits parallel to the rail. Material: Powder Coated Marine Grade Aluminum Ball Size: 1" Rubber Ball "B" Size Note: The "U" in the part number reflects product packaged in poly bag.