The FireAngel ST-622 Thermoptek optical smoke alarm, technology of choice for the UK Fire & Rescue Services, has been discontinued by the manufacturer. This new FireAngel alarm uses the same base plate as the ST-622, with no requirement to drill no more holes in your ceiling or redecorating. The 10-year sealed lithium battery replacement alarm, requires no battery changes for its whole lifespan and automatically activates when attached to the base plate. This optical smoke alarm is ideal for bedroom and living room installations, as it is designed to detect slow, smouldering fires often associated with soft furnishings.