CLASS 2 RATED ALARM SYSTEM PROVIDES OCCUPANTS OF A BUILDING WITH ADVANCED WARNING OF A FIRE IN ANOTHER ROOM: Place fire and smoke alarms in high-risk rooms and opening onto escape routes leading to fire exits, in small and medium-sized premises CONNECT UP TO 24 HEAT AND SMOKE ALARMS, OR UP TO 12 ALARMS WHEN INCLUDING A CARBON DIOXIDE ALARM - When smoke and carbon monoxide alarms are interconnected, each alarm can now tell you when there’s smoke or carbon monoxide in any room that has a detector 9 VOLT BATTERY BACKUP (BATTERY INCLUDED) ENSURES THE ALARM WILL OPERATE IF MAINS POWER IS LOST: The smoke alarm also has test function, fault, and low battery warnings to assist with alarm maintenance HUSH FUNCTION ALLOWS THE ALARM TO BE TEMPORARILY SILENCED: With the alarm volume 85dB(A) at 3 metres, and the smoke alarm is in constant monitoring of the air for the presence of smoke THE HARD-WIRED OPTICAL SMOKE ALARM WIRES DIRECTLY INTO YOUR HOME ELECTRIC SYSTEM: With a dust cover included to prevent contamination of the device during installation – with a 10-year product lifetime, Weight: 0.13007273458 Pounds, Manufacturer: British General