Consists of a zinc coated u-bolt base, short double socket arm and universal spring loaded X-Grip IV cradle for phones Hardware included that will accommodate rails from 0.50" to 1.25" in diameter The base includes black cover caps to be placed over the exposed ends of the u-bolt Composite rail adapter can narrowthe rail to a minimum width of 0.5" The mount is designed with a RAM B size 1" diameter patented rubber ball and socket system that has adjustment points at both ends of the double socket arm; allowing for almost infinite adjustment and perfect viewing angles Spring loaded X-Grip IV cradle expands and contracts, allowing for a perfect custom fit of your phone or phablet Includes a device tether recommended for outdoor applications Minimum Width = 1.875" (Minimum Height = 4.25") Maximum Width = 3.25" (Minimum Height = 2.25") Depth = 0.875"