Worn by anti-zombie military personnel. Yellow Filter from the original concept art: https://www.roblox.com/catalog/13471437613/Toxic-Lab-Gas-Mask-Yellow-Filter This gas mask is from Dead Ahead Zombie Warfare used by the TMF. There is a noticeable difference in design from other gas masks that looks "similar" to this.
Data is not updated in real time. Most stats update within seconds or a few minutes.