The "U" in the part number denotes the packaging. If you're looking for a retail box, please consider RAM-111. The Parts and compatibility are identical between RAM-111 and RAM-111U.
The RAM-111U consists of a 2.5" diameter round base that contains the universal AMPs hole pattern, STANDARD LENGTH double socket arm and 6.25" x 2" rectangle base. The rectangle base 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.
Plate Hole Patterns