Garmin's 010-11927-21 12 Degree tilt B150 Bronze Thru Hull 300W Transducer with CHIRP Technology. Provides a maximum depth reading of 1,500 ft. The B 150M Operating frequency of 95 to 155 kHz. 26/17 degree beamwidth and mounts on a deadrise of 8 to 16 degrees. Compatible with Garmin GPSMAP 527xs, 547xs, 721xs, 741xs, 840xs and 1040xs.