What two components are checked during the preflight of the POB on the ERJ?

During the preflight check of the Portable Oxygen Bottle (POB) on the ERJ, it is essential to inspect both the mask tubing and the protective plug. The mask tubing must be checked to ensure there are no leaks or damage that would compromise its function, as it is vital for delivering oxygen effectively in an emergency situation. Additionally, the protective plug must be in place, as it prevents any inadvertent activation of the oxygen system during normal operations. Together, these components ensure that the POB is ready for use if needed, providing confidence in the safety equipment available onboard.

Other choices do not encompass the complete and necessary checks for the POB's functionality. For example, the weight and location of the POB are important but do not directly relate to the operational readiness of the mask and tubing, which are crucial for passenger safety in emergency scenarios.