LIFPE9M 9V Photoelectric Smoke Alarm with Mute Sensitive to Slow Smouldering Fires Features: Photoelectric sensor suitable for slow smouldering fires Insect screen on the sensing chamber Low profile design (100mm diameter) Red led light for alarm indication and testing Mute & alarm test button Low battery warning signal Simple installation (includes all screws and fixings) Tamper resistant feature Easy twist on twist off installation Complies & Approved to Australian Standard AS3786 Loud 85db alarm 2 year warranty (excludes battery) Specs: Power Source: 9V Battery Battery type: Eveready 1222, Energizer 522, Gold Peak 1604S, Duracell MN 1604, Ultralife U9VL Operating temp: 0°C to 45°C Ambient Humidity: 10%-90% Alarm Sound level: 85 Decibels at 3 metres Battery life: 1 year minimum Detection method: Photoelectric sensor Low battery indication: Chirps when battery needs replacing Alarm duration: As long as smoke is present, resets when smoke clears. Mute mode: When in Mute mode, the unit is desensitizedfor 10 minutes. Mute indication: Red LED flash every 30 seconds for 10minutes, then resets. Tested & Passed to: AS3786-1993 Dimension: 103mm diameter x 40mm high.