The RAM-B-149-GA40U consists of a double socket arm, stainless steel u-bolt base, 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 motorcycle GPSMAP mount to your optimum viewing position. Included in this package is hardware that will accommodate rails from 0.50″ to 1″ in diameter.