The ST transducer was a transom-mount speed and temperature sensor made for Lowrance equipment.
Versions were available with a Uniplug connector (ST-TU), a TX-type connector (ST-TX), and the current 7-Pin blue connector (ST-TBL). There were also speed-only versions for the Uniplug (SP-U) and 7-Pin blue connector (SP-BL).
These parts were not Airmar parts but were manufactured by Navico in Mexico.
Gemeco Marine Accessories is a wholesale distributor to thousands of marine electronics dealers throughout the USA and abroad. Although transducers are our primary focus, we also offer a wide array of networking components and other marine accessories.