Optical Smoke Alarm has a quick response to visibly smouldering fires (e.g. from foam filled furniture & overheated PVC wiring). Please Note: This range has been discontinued, the closest alternative is the Hi-Spec Photoelectric Smoke Alarm. Particularly good in areas where you can otherwise expect false alarms (e.g. near kitchens). Photo electric smoke alarm with Test/Hush button. Complies with CE, BSI, SAI Global approved, EN14604 AS 3786 and the UL217 STANDARD. AC/DC operated, Comes with a 5 year limited warranty, Inter connectable, Battery Back Up (9V PP3 not included), Low battery indicator, Quick fix mounting bracket for easy installation, 2 color LED Alarm indicators, Extra Loud alarm >85dB, Tamper resistant fixing, Auto-reset function.