The Mains Optical Smoke Alarm with Alkaline Battery Backup by Firehawk is a reliable and essential home security device. This smoke detector is hardwired for power source and comes with a photoelectric smoke sensor for optimal functionality. recommended date to change may 2031 and features a white colour, perfect for blending seamlessly into any home decor. The included alkaline battery backup ensures continuous protection during power outages, providing peace of mind for you and your family.