CROWN ELITE Photoelectric Smoke Alarm with 10-year Battery Backup – 240V Mains PoweredSpecifications:Complies with AS3786Power Supply: 240V AC 50Hz with Backup BatteryMaximum Current: <70mAAlarm Volume: >85dB at 3 metersInterconnection: Hardwired up to 22 Smoke AlarmsBackup Battery Lifespan: 10 YearsType of Installation: CeilingDimensions:140mm Diameter x 45mm HeightButton to hush silence nuisance alarmsTest button and LED light indicator visible to verify battery and alarm operationACTIVFIRE CERTIFIEDCertified to AS 3786: 2014: Complies with Australian Standards.