Fire Angel 9B-SB1-TP-R Optical Smoke & carbon monoxide Alarm with 1-year battery Pack of 2. This Fire Angel Smoke & Carbon Monoxide alarm pack will alert you to two dangers in your home
- fire & CO. The smoke alarm in this pack uses an optical smoke sensor which is ideal for detecting slow burning fires. Both units contain replaceable batteries which you can replace once you hear the low battery alert.