A low-linting polyethylene film outer layer that provides protection from contamination. Kimtech Pure M3 Sterile Pleat-Style Masks. 7” - One Size. White. Made of a low-linting polyethylene outer layer and a soft inner-facing fabric; Gamma irradiated with Sterility Assurance Level of 10-6. A fully enclosed soft, bendable nosepiece. Recommended for ISO Class 3 and higher clean room environments. 62467 - Ultra sonically bonded ties. 62470 - Knitted earloops.