RAM Garmin GPSMAP 62 & Astro 320 Holder with U-Bolt Mount, Double Socket Arm & Diamond Base (sku 18639)RAM Garmin GPSMAP 62 & Astro 320 Holder with U Bolt Mount, Double Socket Arm & Diamond Base. This is a double socket arm, zinc coated u bolt base, diamond adapter base and custom high strength cradle for the Garmin Astro 320 & GPSMAP 62. Designed into the mount is a 1" diameter patented rubber ball and socket system with adjustment points at the base and cradle. With a twist of the arm knob, you can move the Garmin mount to your optimum viewing