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.