• The front cover design of the alarm may vary but product function remains the same..
• Help keep your family safe with these battery operated smoke alarms that wirelessly interconnect with each other and other First Alert enabled alarms so that all sound when one is activated, creating a home safety network; comes in a pack of 2 alarms.
• Voice alarm with 11 programmable locations tells you where the danger is so you can choose the best evacuation route; Loud, 85-decibel siren sounds to alert you to danger.
• Equipped with photoelectric smoke sensor optimized to detect larger smoke particles produced by smoldering fires; Helps minimize the number of false alarms, Each detector requires 2 AA batteries for operation.
• Battery powered alarm requires no rewiring for installation and provides continued monitoring even if there's a power failure; use with Polaroid AA batteries for best results.
• Wirelessly connect upto 18 first alert enabled alarms for the maximum in whole home protection; includes test/silence button, low battery warning, end of life timer.
• First Alert has been the most trusted brand in home safety since launching the first residential smoke alarm in 1958 (Based on a First Alert Brand Trust Survey in February 2018).
• Sensor Information: Smoke particles of varying number and size are produced in all fires. For maximum protection, use both ionization and photoelectric sensing technologies. Ionization alarms are generally more sensitive to fast flaming fires and photoelectric alarms are generally more sensitive to smoldering fires..

Product Description ------------------- The FIRST ALERT SA511CN2-3ST Interconnected Wireless Smoke Alarm with Voice Location features an 85-decibel siren and voice alarm that tells you where the danger is located. A photoelectric sensor detects smoke while minimizing false alarms from cooking or shower steam. Interconnected smoke detectors in different locations are designed to work together, with one alarm triggering the other alarm during a fire, helping to provide the earliest warning for your family. From the Manufacturer --------------------- In the event of a fire every second counts. If a fire were to begin in your basement and the alarm there sounded, you may not hear it right away if you're sound a two floors up. With traditional battery-operated alarms, you lose valuable time waiting for the smoke to rise to another alarm, on another level, before the alarm on your floor sounds. But with First Alert ONELINK alarms, if one detects danger, they all sound. This can alert you sooner, and it increases your chances of getting out safely. Until now, alarms that could signal each other were only available in homes with hardwired alarms requiring installation from an electrician. But First Alert ONELINK alarms communicate without wires. ONE Link-with Voice Location Smoke alarm is programmable with up to 11 locations in your home - when alarm sounds it will tell you the location of the smoke. The wireless feature allows multiple alarms to talk to each other - when one alarm sounds, they all sound. The wireless network operates on 914 MHZ 3 channels and will not interfere with other electronics. The ONELINK smoke alarms uses photoelectric sensing technology which is environmentally friendlier and which reduces nuisance alarms, making it ideal for cooking areas. It is also great for sensing slow smoldering fires quickly. A low battery signal alerts you to replace the battery. The test/silence button both silences a non-threatening alarm or low battery warning and allows you to test the unit's functionality. The AA batteries are easy to install in the convenient pullout battery drawer. Two AA batteries included.