RAM® Ball Adapter with AMPS Plate for Garmin GPSMAP 620 & 640

The RAM-B-347-G4 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.