RAM Harley-Davidson Mirror Post Mount, Double Socket Arm, Diamond Base Adapter for GPS Cradles. (sku 18561)The following product is not a complete mounting solution; a RAM GPS cradle is required. The mirror post mount consists of the mirror post base, double socket arm, diamond base adapter. The diamond base adapter measures 61. 7mm x 33. 2mm and contain two holes 48. 5mm from center to center, positioned at both ends of the diamond base. The hole pattern found on the diamond base will connect to many RAM cradles, as well as third party cradles including