Review on 🔥 SA521CN-3ST Hardwired Wireless Smoke Alarm with Photoelectric Sensor and Battery Backup - FIRST ALERT by Eric Rose

Advantages: Easy replacement of an old alarm. New plug included. Cons: No screws in the box. If you are installing a brand new detector in place of a replacement, you will need your own screws to attach the mounting plate to the junction box. It's fine unless you know you need them and the package doesn't mention they're missing. The first one I got was also broken. Everything is connected, the power indicator is green and solid, a triple beep sounds every minute. I put new batteries in as a precaution, but to no avail. The rating will be revised if the replacement works. Edit: Ordered at the beginning of May 2018 and the production date of the device is 12/29/2017. So it's not old stock. 2nd edit: Revain replaced the faulty one and the replacement went fine so far. Rating upgrade from 1 to 3 stars. To get more, both types of fire detectors are needed, at least mention that the screws were not included and that they were not originally faulty.