RAM MOUNTS' RAM-B-176-A-UN7U fork stem mount with short double socket arm and universal X-Grip Cell, iPhone Cradle The RAM-B-176-A-UN7U consists of a fork stem base, short double socket arm, and universal X-Grip cradle. 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. The X-Grip includes a device tether recommended for outdoor applications. The cradle is compatible with handheld devices that will fit the dimensions listed below. It is important to verify the dimensions of your handheld device with a case/sleeve/skin when determining the overall size. This part is designed to fit into the cylindrical bore wall of fork stems and will work with stems that measure from 12 – 33 mm (0.5 – 1.29 in).