The RAM-B-149Z-UN7U consists of a zinc coated u-bolt base, double socket arm and universal X-Grip cradle. Included in this package is hardware 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. The mount is designed with a RAM 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. The included composite rail adapter can narrow the rail to a minimum width of 0.5" The included X-Grip cradle has a clean and clever four leg design that sports great holding power without hiding your phone behind foam pads and plastic The spring loaded X-Grip cradle expands and contracts, allowing for a perfect custom fit of your cell phone and includes a device tether recommended for rugged applications Cradle expands to fit devices 1.875" - 3.25" Depth = 0.875"