Plush 100% Silk Face Mask. This mask is a washable and reusable non-medical mask. Made from 100% Mulberry silk, this mask a has a filter pocket that can be fitted with loose filter material, including any kind of HEPA filter, which may improve effectiveness. Face masks can become contaminated on the outside, or when touched by your hands. If the mask becomes damp or soiled, hand or machine wash cold delicate using gentle detergent. Hang dry or tumble dry low, for 10 minutes.