Announced in 2016 for $109. 99Why Trust UsWe tested, rated and ranked the most advanced smoke alarms on the market today. We chose smart smoke alarms that do more than simply blare an alarm for fire and carbon monoxide emergencies. The products we reviewed are cutting edge devices made for 21st century homes, and they all have mobile apps. While researching for this comparison, we looked into the differences between the sensors each smoke detector uses and found research from Underwriters Laboratories UL that suggests you should have both photoelectric and ionization type smoke detectors in your home since each type is suited for different types of fires. For example, photoelectric sensors do better with smoldering fires that grow slowly and produce a lot of smoke while ionization alarms are better for detecting fast growing, flaming fires. UL is not alone in this recommendation; many other fire safety organizations make the same suggestion. If you want more information on smoke detectors, we recommend checking out the National Fire Protection Association's helpful guide, "Safety Messages About Smoke Alarms. "How We TestedEase of UseOur testing team built a custom apparatus designed specifically to analyze each smoke alarm’s detection capabilities. It was placed in the center of a room measuring 25. 33 x 18.