K-Rain 3208-HRFS Hardwired Rain/Freeze Sensor. The K-Rain Rain/Freeze and Rain Sensors will turn your irrigation controller into an expert water manager by efficiently suspending watering during rain and/or freeze periods. After a set amount of rain has fallen and/or freezing temperatures exist (for models with freeze sensors), the sensor will trigger the controller to suspend watering. Unlike other Rain Sensors in the market, K-Rain’s wireless rain-freeze sensor can be paired with multiple K-Rain Pro EX 2.0 Wifi-enabled controllers within range, providing additional value for the end user. This model is a Hardwired Rain/Freeze Sensor.