 Introducing the Geo SCO2 Wireless Combo Smoke and CO2 Detector for the Geo Alarm. Easy to install. It comes with a built-in 85-Desiple Siren, a built-in test button, UL2034 and UL217 Replaceable 3V lithium batteries, both CR123A and DO123A compatible. This device monitors troubles and supervision issues so that you are always in the loop when it comes to what's going on with this device. Once again, ladies and gentlemen, introducing the Geo SCO2 Wireless Combo Smoke and CO2 Detector for the Geo Alarm. Please like and subscribe to our page for helpful programming and installation videos, product reviews, monitoring, products, and more. Visit www.geoarm.com or call 877-443-6276. That's www.geoarm.com or 877-443-6276. Geo Arm, the worldwide leader in DIY security.