The RAM-B-202-G4U consists of a 1" 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 Mach Screws) and 3x (#8-32 SS Nylock Nuts) that will connect the RAM-202-G4U to the bottom of the Garmin echo™ and Striker™ 4 Series.