The RAM adapter base includes a 1.5" diameter rubber ball and inserts directly to the back of Lowrance Elite 5 and Mark-5 Fishfinders. The adapter serves as a quick release mechanism, allowing you to remove or transfer your Fishfinder in seconds.Compatible Models:Lowrance Elite-5Lowrance Elite-5 DSILowrance Elite-5 GoldLowrance Elite-5xLowrance Elite-5x DSILowrance Elite-5mLowrance Elite-5m GoldLowrance Mark-5xLowrance Mark-5x DSILowrance Mark-5x DSI PortableLowrance Mark-5x ProLowrance Mark-4Lowrance Elite-4Lowrance Elite-4 DSILowrance Elite-4 GoldLowrance Elite-4xLowrance Elite-4x DSILowrance Elite-4m