The Inspector is the guaranteed best portable CO detector on the market. Use it as a simple Carbon Monoxide Meter to monitor the air, or purchase the full analyzer accessory kit to use it as a complete carbon monoxide combustion analyzer. HVAC Technicians, EMTs, Fire Departments, home inspectors, pilots, property owners and industrial users all prefer the Inspector because of its high quality and low cost. Whether you call it a detector, tester, meter, monitor, sensor or just a gadget...you'll like it! Designed and Made in the USA.