Toro Evolution Series Wireless Precision Soil Sensor Wireless Communication Up to 500' (152m) line-of-sight Automatic Calibration The sensor will automatically detect the soil type and adjust all calculations accordingly Freeze Detection The only soil sensor to offer freeze detection that prevents irrigation when temperatures approach freezing Signal Strength Indicating LED A multi-color LED on the sensor probe indicates radio signal strength to assist in finding a suitable installation location Long Battery Life Easily replaceable batteries last up to 2 years with alkaline batteries (longer with lithium)