WSM Standard Wind Speed Sensor
The WSM wind speed sensor has stainless steel ball bearings for greatest accuracy and operating life.  The sensor uses a sealed magnetic reed switch for maximum reliability.  This switch produces contact closures at a rate proportional to wind speed.

The sensor has a starting threshold of 1mph and will operate up to a range of 100 mph.  The WSM includes cable and a waterproof bayonet quick connector.  For harsh conditions see Heavy Duty Wind Speed Sensor.
WSM Specifications

Range: 0-100 mph (0-160 kmh)
Starting Threshold: 1.0 mph (1.6 kmh)
Accuracy: ±0.25 mph or 1.5% (0.4 kmh)
Distance Constant: Less than 15 ft  (4.6 m)
Operating Temperature Range: -60°F to +160°F (-50°C to +70°C)
Weight: 14 oz (400 g)