3M NIOSH N95 Approved Respirator - CDC Recommended against Flu Face Mask - 2 Packs of 40 CDC recommendation to protect against Avian Bird Flu & SARS Approved and meets NIOSH and CDC guidelines Reduces risk of fluid strike-through and protects against micron-size particles; Double bands secure Features a large Breathing Chamber with Advanced Filtration Size: Regular - One Size Fits All / 2 Packs of 40