The RAM-111U consists of a round base with a diameter of 2.5 inches that features the universal AMPs hole pattern, a standard double socket arm in standard length, and a rectangular base measuring 6.25 x 2 inches. The rectangular base has various combinations of pre-drilled holes that are compatible with many electronic devices and mounts, including marine GPS devices, CB radios, amateur radios, gimbal mounts, and more. RAM's double socket arms, with their distinctive hourglass shape, are designed to provide the best possible performance for most applications. The hourglass shape is a registered trademark of National Products Inc.