Ram Mounts RAM Drill-Down Ball Mount for Humminbird Helix 8-10 & XPLORE - This powder-coated, marine-grade aluminum Humminbird mount consists of a short length double socket arm, a 3.68in diameter round base with a 2.25in D size ball, and one 1.5in x 4.5in rectangular plate with a 2.25in D size ball. The round plate contains two mounting holes at 180-degrees and three mounting holes at 120-degrees. The 1.5in x 4.5in rectangular plate contains a 4-hole pattern compatible with Humminbird 8, 9 & 10 models. The 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. Complete flat surface, drill-down mounting solution for the Humminbird XPLORE Series, and Helix 8, 9, & 10; RAM Mounts ball and socket technology allows for near-infinite adjustability Includes 3.68in round base with D size 2.25in rubber ball, short length D size double socket arm, and a 1.5in x 4.5in rectangle base with D size 2.25in rubber ball that connects to your Humminbird Helix marine electronic Made of Powder-coated, marine-grade aluminum for durability and reliability in the most demanding marine environments Manufacturer lifetime warranty Overall Height: 7.875in Top Plate: 2in x 5in Bottom Plate: 3.68in Diameter Ball size: D Size (2.25in)