First Alert Smoke and Carbon Monoxide Alarm, 3-pack $80

Much better price per unit than Amazon’s, if you need 3 units
Shipping & Handling Included*
Features:
Wireless Enabled Battery Operated Smoke and Carbon Monoxide Alarm
Interconnects to Each Other, When One Sounds They All Sound
Voice Alarm Tells Where Potential Danger Exists, Up to 11 Locations
Photoelectric Smoke Sensor, Electrochemical Carbon Monoxide Sensor
Includes Test/Silence Button, 7-Year Limited Warranty
https://www.costco.com/First-Aler…47069.html