The nerdytec mouth masks are made of high quality polyester. They effectively filter small particles from the air and thus protect against smog, dust, odors, exhaust fumes and air pollution. Thanks to the innovative 3D design, it perfectly adapts to any face shape and ensures a tight fit. Comfortable to wear thanks to stretchable elastic ear loops, even over a long period of time. The mouth-nose masks can be conveniently washed and reused. Due to the special memory effect, the mask retains its shape even after many washes! Note: This mask is not a certified mouth guard!