Now, Nest admits on collecting data from your system to analyse the average battery life, it records data about any adjustments you make to the product and the history of all changes, but it insists that all collected data is not sold to third party companies and the info may be shared but not before the user gives explicit permission to do so. The First Alert Onelink Safe and Sound is the newest smoke and Carbon Monoxide detector from the US based manufacturer and it is the second attempt at creating a worthy competitor to the widely popular Nest Protect 2nd Generation. I purposely skipped the first generation of OneLink because it was a mess software wise the app was unstable and the device would constantly trigger false alarms, so the company has worked hard to fix these issues and hoped that this new device would receive more positive feedback from the audience. To further set it apart from its predecessor and its competitors – which are not that many, the First Alert Onelink Safe and Sound has included a built in speaker and has embedded Alexa Voice Services, while also keeping the compatibility with Apple’s HomeKit of course, this has driven the price up significantly. Since the Halo Smoke Alarm got discontinued and the Cloud based support got closed as well, I can understand why people may be reluctant with giving start ups a chance and instead may prefer to go with a more mature company that’s been in the business for longer and that’s where the likes of Nest and OneLink Safe and Sound come into play and remain overall favourites in spite of the usually higher price tags. The First Alert Onelink Safe and Sound detector features a fairly large oval case made of plastic, with the front side divided into multiple inner sections by narrow plastic bands, the device mostly being covered by lots of puncture holes the middle section is slightly elevated. Surrounding the top area there’s a metallic ring while towards the bottom, the case gets significantly slimmer and it features narrow holes all around to allow the smoke to enter the inner chamber. It’s hard not to see the striking similarities with the Nest Protect, which is also covered by lots of small holes on the front side, as well as the overall shape of the smoke detector and the LED light which shines from the circular middle section on both smoke detectors it’s clear that all smart smoke and CO detectors follow the same design pattern, so it’s not surprise that both the First Alert Onelink and Nest Protect look so similar: it seems that developers either think that this is the most ergonomic design or are simply afraid to try something new. Similarly to the Nest Protect 2nd Generation, the Safe and Sound also has a NightLight which can be adjusted in terms of intensity or colour depending on the time of day, but it cannot be set to turn on only during the night while Nest does allow it. The Onelink Safe and Sound alarm is slightly larger than your average non smart smoke detector it measures 6. 8 x 6.