Shop Honeywell Home Wireless Combo Smoke and Carbon Monoxide Detectors at GeoArm Security. Browse 5800-Series (345 MHz) and PROSiX encrypted sensors designed to detect smoke, dangerous carbon monoxide gas, and abnormal heat conditions in residential and commercial properties. These life-safety devices alert the connected alarm system when signs of a potential fire or elevated carbon monoxide levels are detected. Honeywell-Compatible security systems support GeoArm 24/7 professional UL-listed central station monitoring or DIY self-monitoring with no long-term contract.