9v battery smoke alarm series The ionization room adopts single- ... compositive degree, steady performance and long using lifeTiny power consumption, battery as power source, safety, convenient installation, not join other ... function of low voltage, reminding you to replace the battery on timeAdopts double alarm of sound-audio, it can ... 40°CAmbient humidity: over 95%(40±2°C)Low battery Alarm: 6V±0.5V..