Fire Angel Multi-Sensor Smoke Alarm 10 Year Sealed Battery – ST-622 Thermoptek Smoke Alarm10 Year Lifetime BatteryLooking for a Fire Angel ST‑622 smoke alarm replacement? Either Fire Angel’s FA6620‑R or FA6615‑R smoke alarms can replace your end of life ST‑622 without requiring a new base plate or leaving unsightly holes in your ceiling. ThermoptekThe fastest response to all fire types.5 Year WarrantyFor peace of mind. Rapid Alerts to all Fires Thermoptek TechnologyThermoptek technology combines the very latest in optical sensing with thermal enhancement and when compared to single sensor alarms react to fire in under half of the time ‑ meaning you and your family have vital extra time to react.Battery Powered Protection10 Year Battery IncludedThe unit comes with a sealed, tamper proof battery that will last the lifetime of the alarm. The sensor within the unit will deteriorate after 10 years, so to ensure you’re protected we recommend you replace the unit after this time.Testing Made SimpleAs well as allowing easy testing with a sweeping brush from the floor below, this large button also activates our Sleep Easy function which silences low battery chirps for 8 hours ‑ giving you a peaceful night’s sleep.