The marine-grade aluminum RAM® Drill-Down Double Ball Mount for Humminbird Helix 7 features a C-size ball and socket-to-socket length of 4.66 inches. KEY FEATURES Complete flat surface, drill-down mounting solution for the Humminbird Helix 7; RAM® Mounts ball and socket technology allows for near-infinite adjustability Includes 2.5" round base with C size 1.5" rubber ball, medium length C size double socket arm, and a 1.5" x 3.5" rectangle base with C size 1.5" rubber ball that connects to your Humminbird Helix 7 Made of Powder-coated, marine-grade aluminum for durability and reliability in the most demanding marine environments Backed by a lifetime warranty The RAM-202-24-202U powder-coated, marine-grade aluminum Humminbird Helix 7 mount consists of a medium length double socket arm, a 2.5" diameter round base with a 1.5" C size ball, and one 1.5" x 3.5" rectangular plate with a 1.5" C size ball. The 1.5" x 3.5" rectangular plate contains a 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 the Humminbird Helix 7.