The RAM X-Grip Large Phone Mount with RAM Vibe-Safe & Reservoir Base (RAM-B-174-UN10-462) is a combination of the RAM X-Grip Phone Mount with Motorcycle Brake/Clutch Reservoir & Handlebar Base and the RAM Vibe-Safe - our vibration damping accessory is designed to protect electronic devices from a wide range of vibration frequencies. The RAM X-Grip can rotate between portrait and landscape by loosening the center screw. This product comes with one (1) medium B size arm, one (1) RAM Motorcycle Brake/Clutch Reservoir & Handlebar Ball Base that attaches to either the handlebar or brake/clutch that accommodates rails from .5" - 1.25" in diameter and an optional device tether that is recommended for outdoor applications. This kit also includes one (1) zinc-coated metal U-bolt that accommodates rails ranging from 0.5" to 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.