Fireangel FireAngel Optical Smoke Alarm with 5 Year Replaceable Batteries, FA6615-R-T2 (ST-625 replacement, new gen) - Twin Pack & Heat Alarm with 10 Year Sealed For Life Battery, FA6720-R

Product 1: The perfect replacement for FireAngel ST-625 models with a simple swap of the baseplates, or for ST-622, ST-620 and ST-750 models using the existing baseplate

Product 1: With optical sensing technology smoke is rapidly detected as it enters the alarm chamber, for a quick reaction to slow burning fires

Product 1: The alarms are supplied with 4 x AA batteries which can be replaced upon hearing the low battery warning, it is recommended you replace the alarms after 10 years

Product 1: Featuring a quiet test function which means you're less likely to wake up loved ones or disturb the neighbours when testing your alarms

Product 2: Designed for areas with fumes and high humidity, such as kitchens, garages and lofts, the thermistor technology ensures you’re alerted to fires without false reactions

Product 2: The alarm comes with a sealed, tamper proof battery that will last the lifetime of the alarm

Product 2: The quiet test function means you're less likely to wake up loved ones or disturb the neighbours when testing your alarms

Product 2: You may be able to install this alarm onto your existing FireAngel baseplate (HT-630 models) but if not, it only takes 2 screws to update