A low-linting polyethylene film outer layer that provides protection from contamination. Kimtech Pure M3 Sterile Pleat-Style Masks. 9” - One Size. Ultra sonically bonded ties and a fully enclosed, soft, bendable nosepiece. Made of a low-linting polyethylene outer layer and a soft inner-facing fabric; Gamma irradiated with Sterility Assurance Level of 10-6. Recommended for ISO Class 3 and higher clean room environments. White. 9" Soft ties. 20 Unit(s) / Pack.