The X-Grip Large Holder With U-Bolt Double Ball Mount Kit consists of a zinc coated U-bolt base, double socket arm and universal spring loaded X-Grip® IV cradle for large phones and phablets. 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 included composite rail adapter can narrow the 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. The spring-loaded X-Grip® cradle expands and contracts, allowing for a perfect custom fit of your phone or phablet. The X-Grip® includes a device tether recommended for outdoor applications.