Standard Mount: Each Lezyne GPS unit comes with a Standard GPS Mount. Included are two sets of o-rings (two diameters), plus a backup o-ring in each size, a rubber shim and an X-Lock composite mounting bracket. The rubber shim supports the X-Lock mount which is engineered to attach at any 9Â° angle and still allow the computer to be mounted forward. The two super durable o-rings secure it to the bar, and the patent-pending X-Lock design will prevent the computer from being knocked out. The X-Lock securely fastens the GPS computer to the mount by pressing down at a 45Â° angle and rotating it forward until it "locks" into place. Forward Mount: The Forward Mount is a hinged handlebar mount featuring a stiff and durable composite matrix construction with secure X-Lock and an integrated rubber shim. Pressed in stainless steel nut and 3 mm hex stainless steel bolt, this mount's sleek, lightweight design positions the GPS computer in front of the stem for better visibility and improved aerodynamics. The X-Lock is a secure and reliable mounting feature integrated into the Standard GPS Mount and the Forward GPS Mount. It safely locks in the computer for worry-free riding over any type of terrain. O-Ring Mount Kit: GPS Mounting Kit comprised of rubberised O-Rings to help keep your GPS Mount secured to your handlebars.