Shop Resideo Wireless Combo Smoke and Carbon Monoxide Detectors at GeoArm Security. Browse combination sensors designed to detect airborne smoke particles and dangerous carbon monoxide gas, providing early warning of potential fires and hazardous CO exposure. Resideo-compatible wireless smoke and carbon monoxide detectors support GeoArm 24/7 professional UL-listed central station monitoring or DIY self-monitoring with no long-term contract.