Raymarine T221 Mast Rotation Sensor
This unique transmitter compensates for the movement of a rotating mast to ensure that you get the most accurate wind readings at all times. Operating as a wireless device on a Micronet network the Mast Rotation Transmitter compares compass information from the boat with its own information and corrects the wind angle coming from a standard wind transmitter at the mast head. Easily installed at any convenient position on the mast the Mast Rotation Transmitter can be calibrated simply from any Digital or Dual Digital Display in the system. | 
