RAM Double Ball Diamond Plate Mount for Humminbird Piranha + More (RAM-B-107-1U-238) (sku 54647)The RAM B 107 1U, powder coated marine grade aluminum mount, consists of a double socket arm, one 2. 5" diameter round base and connecting Humminbird Eagle Lowrance marine base. The mount is designed with a 1" diameter patented rubber ball and socket system that has adjustment points at the cradle base and bottom base. With a twist of the arm knob, you can move the marine mount to your optimum viewing position. PRODUCT DIMENSIONS Overall Height: 5"