The RAM-202-153-202U powder-coated, marine-grade aluminum Humminbird Helix 5 mount consists of a medium length double socket arm, a 2.5" diameter round base with a 1.5" C size ball, and one 1" x 2.5" rectangular plate with a 1.5" C size ball and 4-hole pattern. Rubber ball and socket technology provides shock and vibration damping, and allows for near-infinite adjustability so you can position your device at the perfect viewing angle. Compatible with versions of the Humminbird Helix 5.