The RAM Mounts RAM-B-138-UN7 RAM Flat Surface Mount with X-Grip Cell Phone Holder consists of a 2.5” (6.35cm) diameter round base with the universal AMPS hole pattern, a double socket arm, and a universal spring-loaded X-Grip holder for cell phones. Within the mount is a 1” (2.54cm) diameter rubber ball and socket system with adjustment points at both ends of the socket arm. This allows you to move the mount to the optimum viewing position with a twist of the arm knob. The included X-Grip cradle has a clean and clever 4-leg design that sports great holding power without hiding your phone behind foam pads and plastic. The spring-loaded X-Grip holder expands and contracts, allowing a custom fit to your cell phone.