Install Additional Nest smart smoke and CO2 detector – Battery Operated – PNW Home Improvements
First Alert SC9120B Hardwire Combination Smoke/Carbon Monoxide Alarm with Battery Backup | First Alert Store
SafeTAlert SA339 White RV Battery Powered CO2 Detector SA339WHT - Atlantic Rigging Supply
BRK First Alert - CO5120BN Hardwire Carbon Monoxide Alarm with Battery– Wholesale Home
Kidde 10-Year Worry Free Smoke & Carbon Monoxide Detector, Lithium Battery Powered with Photoelectric Sensor and Voice Alarm 21030866 - The Home Depot
First Alert 10-Year Battery-Operated Smart Combination Smoke and Carbon Monoxide Detector with Voice Alert in the Combination Smoke & Carbon Monoxide Detectors department at Lowes.com
Safe-T-Alert SA-340 White RV Battery Powered CO2 Detector - Rectangle - SA-340-WT | Anchor Express