The RAM Quick-Grip™ device mount is capable of holding a broad range of electronic devices. The spring loaded mechanism and the adjustable side keepers allow for a secure grip on your device. Whether it is a cell, GPS, blue tooth speaker or anything that will fit in the dimensions of the cradle, your electronics will be secure. Features: Cradle clamping dimensions: Height range: 4.75" - 5.75". Width range: 2.19" - 3.25". Max depth: 0.72". Material: Marine-grade aluminum and high-strength composite. Ball size: 1" rubber ball "B" size. Backed by a lifetime warranty. Detailed Specifications: Includes U-bolt base that accommodates rails from 0.5" to 1.25" in diameter and a short length, B size RAM double socket arm; ball and socket technology allows for near-infinite adjustability.