monitoring alarm system
$130, a hardwired smart smoke and CO detector. Most actually review the Halo +, a model that adds weather alerts, and $20, to the regular Halo, but that model is not currently available. Still, core functionality should be the same, and that's well liked by the experts that have seen the unit. It's the top rated smart smoke detector at Reviewed, the second highest rated model at Top Ten Reviews, and earns a 4 star rating from CNET. User reviews are both limited and uninspiring, though, so we think the Nest is a better bet for most, for now. One plus compared to other smart smoke detectors is that it contains both ionization and photoelectric sensors for detecting all types of fires.