RAM EZ-Roll'r Composite Drill-Down Mount for Garmin GPSMAP 78 + More (RAP-B-140-GA40U) (sku 54927)The RAP B 140 GA40U consists of a double socket arm, 2" x 2. 25" rectangular base with the universal AMPS hole pattern, diamond adapter base and custom high strength composite cradle for the Garmin GPSMAP 78 series. 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 flat surface GPSMAP mount to your optimum viewing position.