Nest ProtectThe Nest Protect is our top smart smoke detector. Not only does it detect both carbon monoxide and smoke, but it will also tell you where the source of the fire is bedroom, basement, etc. It will additionally send you an alert on your phone if you're away from home. The Nest Protect can also be connected with a number of other smart home devices and performs a monthly self checkup to ensure that it's working properly. It's more expensive than other smart smoke detectors, but it's a worthwhile investment. Credit: Philips/TP Link/NestUsually, smoke detectors aren’t known as improving the aesthetic value of your room, but the Nest Protect is the better looking one from the bunch. The detector features a rectangular case, with rounded corners and on the the front, the device is covered by lots of puncture holes, with a solid circular button in the middle which is surrounded by a small canal to make way for the LED light to break through it looks surprisingly similar to a speaker. Turn the device around and you can see four narrow, but fairly long ventilation holes on the edges, four holes for ceiling mounting, a battery door and a micro USB connector in case the smoke detector needs servicing. This is available for the battery powered Nest Protect, but, of course, you can also purchase the wired variant, which will have additional AC connector pins on the back side to attach a 230V cable connector. The device itself is not really bigger than the average smoke detector from the market, measuring 1.