RAM Drill-Down Mount for Garmin Astro 320, GPSMAP 62 & 64 Series (RAM-B-138-GA41U) (sku 54774)The RAM B 138 GA41U consists of a 2. 5" diameter round base with the universal AMPS hole pattern, double socket arm, diamond adapter base and high strength composite cradle. The mount is designed with a RAM 1" diameter patented rubber ball and socket system that has adjustment points at both ends of the double socket arm; this allowing for almost infinite adjustment and perfect viewing angles. HARDWARE INCLUDED Assembly Hardware SOCKET TO SOCKET