Mains Powered with 10 Year Lithium Battery Back-up. Designed with installers in mind, this compliant, flexible, easy to fit range delivers advanced sensing technology including Smart RF interlink ensuring your domestic installations are safe for years to come. Designed and developed for kitchens, these alarms feature unique Thermistek sensing technology combined with a patented radiant heat dish, high-performance thermistor and predictive monitoring to ensure a quicker response.