What feature helps reduce CO2 and fogging in the mask?

The nose cup is designed to effectively reduce carbon dioxide levels and minimize fogging in the mask. This feature is instrumental because it helps create an efficient airflow within the mask. By directing exhaled air away from the lens, the nose cup prevents the buildup of heat and moisture that typically leads to fogging, thereby enhancing visibility for the user.

Additionally, the nose cup’s design helps to maintain a better seal around the face, which is crucial for overall respiratory safety. With an effective seal and proper airflow management, the inhaled air remains fresher, reducing the concentration of CO2 that could otherwise accumulate in a restricted environment. This ultimately contributes to safer and more comfortable usage of the respirator or mask in fire practice situations.

Other features such as lens coating, adjustable straps, and external filters may serve different purposes, but they do not directly address the dual issues of carbon dioxide buildup and fogging in the same effective manner as the nose cup.