The RAP-B-111U consists of a 2" x 2.5" rectangle base, STANDARD length double socket arm and 6.25" x 2" rectangle plate. The rectangle base contains pre-drilled holes, including the universal AMPS hole pattern. The 6.25" x 2" rectangle plate contains different combinations of pre-drilled holes which will match up to many electronic devices and mounts, including Marine GPS, CB Radios, Ham Radios, Gimbal Brackets and more.