Naroo F1s - Reusable Anti-Dust Cooling Breathable Sports Mask with UV Protection for Cycling Running Biking (Medium, Black)

Unlike well-made N95 masks with at least 2 straps to distribute the load on the head and neck, this mask only anchors over the neck and serves to strain the musculoskeletal system of the neck. If this is re-engineered, the mask would be more functional. As for the mask, it allows roughly 75% CO2 for O2 exchange with exercise. There doesn't appear to be a mask on the market that filters well while allowing for vigorous exercise (roughly < 65% of VO2 Max), without compromising this delicate physiological process to occur.