Nest Protect features a glowing status ring (green means everything is okay, yellow gives you a warning about a potential problem and red means there’s an emergency) and an interactive sensor that responds to the wave of a hand.
“We started from scratch—after all, this device constantly samples the air in your home, but you have no idea what it’s doing 99% of the time. Instead of only howling about danger, why doesn’t it tell you that you’re safe? Why can’t you go to bed knowing you’re protected? And why can’t it message your phone if something’s wrong? Why can’t it be better?”
The Nest Protect is available to pre-order in the US for $129 and the UK for 109UKP.
source Nest Protect