Ships with the 5625 and 8000 machines. For jobsites where carbon monoxide could be present, the badge can detect as little as 100 ppm carbon monoxide gas at approximate relative humidity range of 33 to 50 percent. If the humidity is very high, it can detect concentrations as low as 20 ppm. The presence of CO changes the sensor from red to gray/black as the concentration level increases. Once the detector is exposed to fresh air, it will return back to red. Once opened the badge lasts approximately 90 days. Adhesion strip on the back, or optional lapel clip mounts almost anywhere.