CO Detector BCN 1221. Protects against poisonous carbon monoxide (CO). • For use in garages, living quarters with open fire places or when camping. • Durable, modern electro-chemical sensor. • Alarm signal and LED display. • Regular self-testing. • Shrill alarm - 85 dB. • Warning signal when battery is running low. • Battery operated 9 V, can be installed anywhere. • 9 V battery included.