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

The RAM-B-347-G4 base consists of a 1" (25.4 mm) diameter rubber ball connected at right angles to a 2" (50.8 mm) x 1.7" (43.2 mm) 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.