The RAP-B-202-153-354-TRA1U consists of a Track Ball base, composite double socket arm and 1.5" x 3" rectangular plate. The rectangular plate contains four holes that will line up with the Humminbird Helix 5. The Track Ball will connect to virtually any track system including the RAM Tough-Track T-Bolt Dimensions: .48" x .95" Overall Length: 5"