Garmin Transom Trolling Transducer f/echo™ Series Fishfinders - 4 PinUpgrade your fishing setup with the Garmin Transom Trolling Transducer for echo series fishfinders a versatile dual beam transducer designed to be mounted on either your transom or a trolling motor. This essential accessory lets you use your echo series fishfinder across multiple vessels with ease, expanding where and when you can fish with precision. Overview The dual beam transducer delivers reliable sonar performance for echo series fishfinders,