Chaoos Mini 3-in-1 Carbon Monoxide Detector, Portable CO Monitor Temp/Humidity Sensor with Lanyard, CO Alarm 0-1000PPM Detection Range CO Air Quality Monitor 1000mAh Battery, for Home/Travel (D6-Blue) - Amazon.com
testo 317-3 - CO Monitor | Gas | Flue gas, gas and particle | Parameters | Testo Ltd