Wireless Control Switch with CO2 Sensor + Power SupplyA wireless 4 speed switch allowing you to manually adjust ventilation rate with a built in CO2 sensor. When the sensor measures a rising CO2 level the MVHR unit will boost to bring in fresh air to reduce CO2 levels (If the ventilation unit is controlled by one or more CO2 sensors, the air flow rate is based on the highest measured CO2 content) Can be used on Flair units (later than 2022) and Ease units Suitable for battery operation or hard wiring