The RAM® Quick-Grip™ XL Phone Mount with RAM® Vibe-Safe™ & U-bolt Base - Short (RAM-B-149Z-A-PD4-462) is a combination of the RAM® Quick-Grip™ XL Phone Mount and the RAM® Vibe-Safe™ - the vibration damping accessory is designed to protect electronic devices from a wide range of vibration frequencies. The RAM® Vibe-Safe™ is based on an NPT connection point and boasts the versatility to rotate between portrait and landscape while keeping your device secure in rugged environments. This product includes one (1) short B size arm and one (1) RAM® U-bolt Base that accommodates rails from 0.5" - 1.25" in diameter. The holder 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. RAM® Vibe-Safe™ dampens a wide range of vibration frequencies.