The RAM-B-149Z-GA40U consists of a double socket arm, zinc coated 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 1.25" in diameter.