Our brand "Zmile", the mask brings you many perfect features: 1. No ncur any allergy. 2. Prevent cross-infection 3. Reusable/washable 50-time still keeps the function of reducing 99.92% bacteria. 4. Adjustable ear loops 5. Avoid glasses fog up by flexible covers on noise bridge and chin. Our JM TTA nano-material and the mask have approved by many experiments of bio-laboratories and gained the certificates, you can check them on our website. Please click below link for comprehension.