The RAM-D-202-25-C-202, powder coated marine grade aluminum mount, consists of a double socket arm, one round 3.68" diameter round base and one 2" x 5" rectangular plate. The round plate contains two mounting holes at 180-degrees and three mounting holes at 120-degrees. The rectangular plate contains a 4-hole pattern of 1.5" x 4.5". The patented rubber ball and socket technology dampens shock and vibration, and allows for nearly infinite adjustability, So you can set your device at the perfect viewing angle, while suited for any rugged environment. Compatible with the Humminbird Helix 9, Humminbird Helix 10, and the Humminbird Helix 12.