RDJ100RF battery powered, wireless, digital, daily programmable room thermostat and receiver. Range 20 metres line of sight between transmitter and receiver. Features large display and control dial, four operating modes - Automatic, Comfort, Energy saving and Frost protection, volt free relay contacts and advance/override facility. The digital display shows operating mode, actual room temperature and the ON/OFF times. When visible, the triangle symbol indicates a heating demand and the battery symbol indicates that the batteries need replacing.