RAM MOUNT X-Grip Large Phone Mount with Torque Rail Base - MediumTake your mobile entertainment on the road with the new RAM Torque handlebar and rail mounting base. Weve paired a B size 1 rubber ball base that accommodates bars 3 8" to 5 8 in diameter with a B size standard length arm and the dynamic X Grip for larger phones. Sizing inserts are included to provide a snug fit and offer additional protection for the rail. The mount utilizes nylon insert lock nuts to prevent loosening in high vibration environments.