RAM 2.5″ Round Base with the AMPs Hole Pattern, 1.5″ Ball & Hardware for Garmin’s echo™ 200, 500c & 550c The RAM-202-G4U consists of a 1.5″ diameter rubber ball connected to a flat 2.5″ diameter base. This mount has pre-drilled holes, including the universal AMPS hole pattern. Included are 3x (#8-32 x 5/8″ PH PD [...]