The RAP-B-101U-LO11 consists of a composite 2.5" diameter round base with the universal AMPS hole pattern, composite double socket arm and adapter base that inserts directly to the back of Lowrance Elite-4 and Mark-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.Compatible Devices:Lowrance Elite-4Lowrance Elite-4 DSILowrance Elite-4 GoldLowrance Elite-4xLowrance Elite-4x DSILowrance Elite-4mLowrance Mark-4