Description: True Heading AIS (Automated Identification System) Class B Transponder is a way of identifying a vessel's position, course and speed and freight through VHF digital information. AIS helps resolve the difficulty of identifying ships when not in sight (e.g. at night, in fog, in radar blind arcs or shadows). True Heading's AIS Class B Transponder provides high performance and low cost Reception and Transmission all in the same unit.