The 34-08701 consists of a double socket arm, 2.5" diameter round base with the universal AMPS hole pattern and connecting Humminbird/Apelco marine adapter base. The mount is designed with a RAM 1.5" diameter patented rubber ball and socket system that has adjustment points at both ends of the double socket arm; this allowing for almost infinite adjustment and perfect viewing angles. Rubber ball and socket technology allows for almost infinite adjustment and perfect viewing angles. 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 Fish finder with matching hole pattern