Sends alerts to your phone in case you aren’t home., The Split-Spectrum Sensor detects fast and slow burning fires., It’s the first home smoke alarm you can hush right from your phone or tablet without any extra hardware required., It speaks up to tell you what’s wrong and where the problem is., Keeps you safe and sound for up to 10 years. The longest time allowed by law. Please note: The Nest protect can have the alarm hushed by pushing the button as long as its not a severe alarm. If you are having a severe smoke alarm the ring will glow red and because the Protect is detecting high amounts of smoke and believes you are in danger. If you are going to stay in the area you will have to remove the Protect so it no longer detects the smoke, or remove the batteries from it to shut off the alarm. The Second Generation has a tab on the back for easy access to the batteries.