Best Buy: Google Nest Protect 2nd Generation (Battery) Smart Smoke/Carbon Monoxide Alarm (3-Pack) White S3006WBUS
Fire drill: can Tony Fadell and Nest build a better smoke detector? - The Verge
Google Hardwired Smart Combination Smoke and Carbon Monoxide Detector with Voice Alert in the Combination Smoke & Carbon Monoxide Detectors department at Lowes.com