Slave unit for the Os Varme Snow Sensor 2 snow-and-ice detection controller, adding a switched 16 A output to expand a snow-melting installation across multiple zones. The slave takes its control signal from the master sensor and switches the associated heating cable circuit when snow and moisture are detected. Typical applications include large driveways, ramps, roofs, and gutters where a single master controller supervises several heated areas. HS code 8536.90.