The RAM-B-149Z-GA48 consists of a double socket arm, zinc coated u-bolt base, diamond adapter base and custom high strength composite cradle for the Garmin eTrex 10, 20 and 30. 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 eTrex mount to your optimum viewing position. Included in this package is hardware that will accommodate rails from 0.50" to 1.25" in diameter. Also included are black cover caps to be placed over the exposed ends of the u-bolt and a composite adapter that can narrow the rail to a minimum width of 0.5".