Detects slow, smouldering fires commonly produced by electrical fires or sofas and is less likely to react to cooking smells if fitted in the hallway next to the kitchen. Contains a sealed-in, tamper-proof 10-year lithium battery. Features built-in RadioLINK+ wireless interconnection technology which uses radio frequency signals to link alarms together for added functionality. All RadioLINK+ alarms and devices should be house-coded together upon install. Alarm is not powered until it is twisted on the mounting base, thus avoiding battery power consumption during storage and prior to installation.