CARBON MONOXIDE ALARMS FOR HOME: High quality electrochemical sensor detects dangerous levels of carbon monoxide (co), which alerts you with 4 loud 85db(a) (at 3 metres) chirps and a flashing red led light 10 YEAR SEALED LITHIUM BATTERY: The sealed, tamper proof 10 year lithium battery lasts the life of the alarm, the alarm will indicate when the alarm needs replacing. ALARM MEMORY: If the co alarm activates in your absence, the alarm will continue to alert until there are safe levels of co. the red alarm indicator will continue to flash once every 4 seconds for 72 hours following activation to show co has been detected and the alarm has activated. EASY SET UP GUIDE: Slide the alarm downwards onto the activation base plate and you will hear the alarm CHIRP once and flash 5 times. Press the test button then RELEASE after 3 SECONDS, the alarm will sound after releasing. The activation base plate must be inserted for the alarm to work whether free-standing or wall mounting. No wiring required, simply fixed to a wall or free standing in your home. discrete, modern design to fit into the look of the home. SAFETY ASSURED: Trust Black+Decker quality with this Carbon Monoxide Alarm, certified to BS EN 50291-1:2018 and BS EN 50291-2:2019 and fully compliant with CE and UKCA standards. Perfect for home or leisure spaces.