The RAM-B-101-C-LO11 consists of a 2.5" diameter round base with the universal AMPS hole pattern, long double socket arm and adapter base that inserts directly to the back of Lowrance Elite-4, Mark-4 and Hook-4 Fishfinders. The adapter serves as a quick release mechanism, allowing you to remove or transfer your Fishfinder in seconds. Designed into the mount is a 1" diameter patented rubber ball and socket system with adjustment points at both socket ends of the arm this with RAM's rubber ball and socket technology allows for almost infinite adjustment and perfect viewing angles.