Top 7 Best Optical Fire Alarm

✔Easy installation
✔Test button tests unit's electronic circuitry horn and battery function
✔UL Certified, 10-year limited warranty
✔Test-silence button - allows for test & silence of alarm
✔Ionization sensing technology - smoke detector detects invisible fire particles, 85 decibel alarm alerts of fire

✔Worry-Free After-Sales Services: All X-Sense smoke detectors come with a 60-day money-back guarantee, a 5-year warranty, and lifetime customer support; easy-to-follow instructions are included for convenience; feel free to contact us if you have any questions
✔Quick and Easy Installation: No need for rewiring, as the battery-operated smoke alarm is easy to install with the included screws, anchor plugs, and mounting bracket, or just use an adhesive magnetic pad (sold separately) to effortlessly install it on a wall or ceiling
✔10-Year Battery Life Smoke Detector: Equipped with a sealed 10-year lithium battery for continuous power with no replacement required during the 10-year life of the alarm

✔10-year carbon monoxide sensor. Carbon monoxide is odorless, invisible and deadly. When there’s CO, Nest Protect tells you where it’s hiding.
✔Split-Spectrum Sensor. In an emergency, seconds count. Nest Protect uses two wavelengths of light to look for both fast and slow burning fires.
✔Tells you what and where. It speaks up to tell you if there’s smoke or CO and where the problem is, so you know what to do. Connectivity: Bluetooth 4.0 LE, Wi-Fi 4 (802.11n)
✔With Safety Check you can test all your smoke and CO alarms with just a tap and get a full report once the test is done
✔A Light in the Dark: Usually Nest Protect has its light turned off but when you walk underneath it Pathlight can light your way.
✔With App Silence you can silence the smoke alarm with your phone in the Nest app when there's only a little smoke
✔Get phone alerts so you know something's wrong even when you're away from home[1]
✔Smoke detector and carbon monoxide detector that speaks up in a friendly voice to give you an early warning when there's smoke or CO in your home

✔It can ship within the US except New York
✔Simple to use, with a single test/silence button; EZ access battery drawer allows you to change battery without removing alarm from ceiling
✔Indicator lights on the face of the unit display the presence of smoke or carbon monoxide, while an 85 decibel siren provides a clear, loud warning upon detection
✔Keep your family safe with this battery operated smoke and carbon monoxide alarm; Battery powered alarms provide continuous monitoring of CO levels, even if there's a power failure

✔UL Certified, 10-year limited warranty
✔Test-silence button - allows for test & silence of alarm
✔Ionization sensing technology - smoke detector detects invisible fire particles, 85 decibel alarm alerts of fire

✔UL Certified, 10-year limited warranty
✔Protects during a power failure - combo smoke and CO alarm operates on 2-AA batteries
✔Fire & CO detector in 1 unit with alert modes, LED lights, & voice alarm, that states, "Fire Fire", "Warning Carbon Monoxide", or "Low Battery"

✔85 decibel alarm
✔Inter connectable with BRK and first alert hardwired smoke and carbon monoxide alarms
✔120 volt hardwire smoke alarm with photoelectric sensor and battery backup