We have 3 models of anemometer to test the wind moving in high/middle/low speed. Main Technical Specification: Anemometer for high-speed, Model GCFJ25 Measureing range: 0.8-25m/s Starting wind speed: ≦0.6m/s Diamension: 90x39x78mm Anemometer for middle-speed, GCFJ10 Measureing range: 0.5-10m/s Starting wind speed: Diamension: 90x39x78mm Anemometer for middle-speed, GCFJ5 Measureing range: 0.3-5m/s Starting wind speed: ≦0.2m/s Diamension: 90x39x78mm Absolute value of NON-linearity error: ≦0.1m/s