ADVANCED MULTI-SENSOR FIRE DETECTION: Equipped with both an optical smoke sensor and a thermistor heat sensor, this BLACK+DECKER multi-sensor alarm provides rapid detection of both slow, smouldering fires and fast-flaming fires — ensuring enhanced safety for your home. 10 YEAR BATTERY INCLUDED: Enjoy a decade of reliable safety, no battery changes needed for the entire lifespan of your Black+Decker smoke alarm. The sealed, tamper proof 10 year lithium battery lasts the life of the alarm. The alarm will indicate when it needs replacing REDUCED FALSE ALARMS: Designed with high-quality sensors that are less sensitive to everyday cooking fumes, helping minimize unwanted activations. Ideal for living areas, bedrooms, and hallways, avoid placing near kitchens or steamy bathrooms. EASY SET UP GUIDE: Insert the alarm onto the activation back base plate and twist the alarm firmly clockwise until you hear a ’CLICK’ then press and HOLD the test button for at least 3 SECONDS until you hear the alarm sound. If the alarm doesn’t sound after 3 seconds, twist the alarm firmly clockwise to try again. SAFETY ASSURED: Alarm memory flashes every 4 seconds for up to 72 hours after activation to indicate prior smoke or heat detection. Quality assured and Kitemark certified by the British Standards Institute (BSI) to BS EN 14604:2005+AC:2008 and BS 5446-2:2003 standards., Weight: 0.27337320488 Pounds, Manufacturer: BLACK + DECKER