Product Name: Carbon Monoxide Detector Alarm Sensitive White Co Detector Alarm Model NO.: LM-201A Infrared Sensor Installation: Ceiling Types of Smoke Detectors: Gas Detectors Type: Combustible Gas Detector Origin: Zhejiang, China Product Description Theunitis a photoelectric smoke alarm device.With the photoelectric technology, it is more sensitive to detecting slow smolder fires which general thick, black smoke and may smolder for hours before bursting into flames. The smoke alarm devicedoesnot contain the radioactive material which is harmless to the environment.