Tacktick T120 Wind Transmitter. For the first time, you can have wind information without running cables down the mast. The Wind Transmitter measures Wind Speed and Direction and sends data to any Micronet display via wireless link. It can be fitted (simple three-screw attachment) with the mast in place and makes un-stepping the mast easy too. Calibration for wind speed and direction is done at any display. Solar powered. No cables. 300 hours autonomy. Only 230g (0.51 lbs). Full calibration via displays.