RAM Pin-Lock Universal Marine Electronic Mount (RAM-S-D-111U-C) (sku 54809)The RAM S D 111U C consists of a 3. 68" diameter round base, SHORT LENGTH double socket arm, 11" x 3" rectangular base, RAM mixed combination Pin Lock security nut and key knob. The round base contains pre drilled holes, including two holes at 180 degrees and three holes at 120 degrees. 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