Dro-Med Medical N95 with Valve. 12 pcs per box. Meets CDC (Centre for Disease Control and Prevention) guidelines for M. Adjustable head band straps on cheeks allowing optimum fit, A non-metal adjustable nose clip for ease of moulding onto nose, Polyester synthetic material preventing allergies Lightweight and comfortable to use, The exhalation valve promotes cool and comfortable breathing within the mask by removing hot exhaled breath, making the respirator easier to use, especially in hot humid environments.