Mains Powered Optical Smoke Alarm with Battery Back-Up BG SDMOA Hard-wired optical smoke alarm Interconnecting: connect up to 24 heat and smoke alarms, or up to 12 alarms when including a CO alarm 9V battery backup ensures the alarm will operate if mains power is lost (battery included) Includes dust cover to prevent contamination during installation Hush function allows the alarm to be temporarily silenced Test function, fault, and low battery warnings to assist with maintenance Class 2 alarm Alarm volume 85dB(A) at 3m Certified to BS EN 14604:2005/AC:2001, BS Kitemark number KM 762034, UKCA and CE Certified As a professional in the industry, you can trust in the BG SDMOA Mains Powered Optical Smoke Alarm. This hard-wired alarm can be interconnected with up to 24 heat and smoke alarms, or up to 12 alarms including a CO alarm. With a 9V battery backup, dust cover, hush function, and maintenance warnings, it provides reliable and certified protection with Class 2 alarm volume reaching 85dB(A) at 3m. . Brand BG Battery Size 9V Colour White Decibel Rating 85 dB[A] @ 3 m Dimensions (Dia)132 mm x (D)43 mm Guarantee 10 Years Hush Facility Yes Interconnectable Yes Maximum Operating Temperature 40°C Minimum Operating Temperature 0°C Mounting Ceiling / Wall Shape Round Standards BS EN14604:2005/AC:2008 Test Facility Yes Type Optical