Raymarine T121 Hull Transmitter [T121] Anchoring & Docking All Fortress Anchors are precision-machined

All Fortress Anchors are precision-machined for sharpness and quick penetration into common sea bottoms

The rate of transmission is increased by more than 30% compared to conventional fish finders

Has same hole pattern as some older version transducers

PiranhaMAX 30PT

"up" for cruising

Raymarine T121 Hull Transmitter [T121] Anchoring & Docking All Fortress Anchors are precision-machinedRaymarine T121 Hull Transmitter *For multi hulls, advanced Micronet technology allows your displays to use wind direction to automatically determine which hull transducer supplies the information you need. No switches required. *Note: you need two hull transmitters for this configuration. Quick Guide (pdf) Owner's Manual (pdf)