The RAM-B-149Z-GA25LU consists of a zinc coated u-bolt base, double socket arm, locking knob, diamond adapter base and custom high strength composite locking case. The locking case features the ability to secure your Garmin nuvi in place, adding much needed protection and enables full access to the screen, power plug, and memory card slot. The case consists of a front and back cover that can be secured together using standard pop rivets or security screws (not included.) The RAM cradle features a unique cable retention system that prevents accidental unplugging of the USB cable. Included in this package is hardware that will accommodate rails from 1.27cm (0.50") to 3.18cm (1.25") in diameter. The base includes black cover caps to be placed over the exposed ends of the u-bolt. The included composite rail adapter can narrow the rail to a minimum width of 1.27cm (0.5") . The mount is designed with a RAM 2.54cm (1") diameter patented rubber ball and socket system that has adjustment points at both ends of the double socket arm; this allowing for almost infinite adjustment and perfect viewing angles.