Manufacturer: Nunotani Nautical Instruments Mfg Co., Ltd
Model: 21S

The propeller in the transmitter is rotated by the wind, and the generator inside generates power. Wind velocity is measured through utilizing the proportion between the power output and the rotation and the wind velocity. The angle of wind direction is communicated to the self-synchronizing machine inside, and directions are sent through remote transmission utilizing its synchronicity.

Set receiver 21S

Wind Indicator
Receiver

21S, F21S: With illumination
21SE, F21SE: Without illumination