Features: 1) Alarm dimensions: 5.5" dia., 1.6" height 2) Working current: a) Static current: lee than 10μA b) Alarm current: less than 12mA 3) Operating voltage: DC 9V 4) Audio alarm: 85dB at 10 feet 5) Temperature range: 14癋 (-10癈) to147癋 (60癈) 6) Humidity range: less than 95%RH (40?癈) 7) Battery: 9V battery back-up for at least 1 year 8) Sensor: Optical