The RAM-B-107U-238 consists of a double socket arm, diamond base and connecting Humminbird/Apelco marine base. Designed into the mount is a 1″ diameter patented rubber ball and socket system with adjustment points at both socket ends of the arm. The diamond base contains two holes 1.912″ from center to center, positioned at both ends of the base. Rubber ball and socket technology allows for almost infinite adjustment and perfect viewing angles. This mount is compatible with the following electronic devices: Humminbird 700 Series Humminbird 500 Series Humminbird 300 Series Humminbird 100 Series Humminbird Matrix Series (excluding Matrix 97) Lowrance Elite-5 Lowrance Elite-5M Lowrance Elite-5X Raymarine Apelco Fishfinder with matching hole pattern Ball Size: 1″ Rubber „B” Ball Size Material: Powder Coated Marine Grade Aluminum Note: The „U” in the part number reflects product packaged in poly bag.