Check the listing for details. RAM Mount 2.25" Ball 3.68" Base Humminbird HELIX 9/10/12 -RAM-D-202-25-C-202U. Condition: New. Listed at 119.99 USD. Manufacturer DescriptionRAM 2.25" Ball Mount with 3.68" Round Base & 2" x 5" Rectangular Place for the Humminbird Helix 9, 10 & 12 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 veiwing angle, while suited for any rugged environment.Compatible Devices:Humminbird Helix 9Humminbird Helix 10Humminbird Helix 12Features and TipsHere is a list of 2.25 in Ball Mount w 3.68 Round Base and 2 in x 5 in Rectangular Place features, along with a few user tips. Weight Capacity: Up to 15 lbs.Overall Length: 7.875"