The Toro EVO-WS Wireless ET Weather Sensor makes saving water easy through the automatic management of the irrigation schedule. Combining real-time temperature and sunlight measurements with location-based ET (evapotranspiration) data, the Wireless ET Weather Sensor wirelessly communicates seasonal adjustments to the EVOLUTION® Series controller. The EVOLUTION controller uses the information to automatically adjust the scheduled runtimes, helping to ensure the landscape receives just the right amount of water.