Which of the following components is NOT part of the MSA G1 SCBA?

The MSA G1 SCBA consists of several essential components designed to provide firefighters with breathable air in hazardous environments. Among these components are the facepiece, which protects the user’s face and allows for clear visibility while ensuring a tight seal; the harness system, which secures the SCBA to the user's body while providing comfort and mobility; and the electronic control module, which helps monitor air supply and can provide critical information during use.

The fire extinguisher, however, is not part of the MSA G1 SCBA. It serves a different purpose entirely, as it's a device used to suppress fires rather than a breathing apparatus that is designed to provide a safe air supply to individuals entering dangerous environments. Therefore, recognizing the distinct roles of each component is crucial in understanding the SCBA system's functionality and safety features.