RAM Mount 1.5" Ball Mount w/2.5" Round Base, Short Arm 2" x 4" Plate f/Humminbird Helix 7 Only [RAM-202-24-B-202U]1. 5" Ball Mount with 2. 5" Round Base, Short Arm & 2" x 4" Plate for the Humminbird Helix 7 Only The RAM 202 24 B 202U, powder coated marine grade aluminum mount, consists of a short double socket arm mount, one round 2. 5" diameter round base with the universal AMPS hole pattern and one 2" x 4" rectangular base. The unique rubber ball and socket technology dampens shock and vibration while offering high adjustibility to achieve the perfect viewing