The RAM® Large Marine Electronics Mount (RAM-D-111U-E) is a complete, drill-down mounting solution for fish finders, chartplotters, and other large electronic devices. This kit consists of D size components, including a 3.68" diameter round base, long-length double socket arm, and 11" x 3" rectangular adapter plate. The round base is pre-drilled with several combinations of holes, including two holes at 180° and three holes at 120°. The adapter plate contains different combinations of pre-drilled holes which will match up to popular electronic devices and gimbal brackets. Included are four shoulder washers that allow smaller hardware to fit properly in the large holes of this plate.