Product description KF94 Medium Size: 5.43 X 7.48 (inch)Produced by a company specializing in filtration manufacturing: Using high-quality MB filters made by the Clean & Science and made in Korea. It is a KF94 mask officially certified by the Korean Food and Drug Administration and has 4 layers of protection.CORRECT USE: Please use mask correctly to avoid serious consequences caused by improper use 1?? Open and put on the respirator to cover your nose and chin 2?? Buckle the ear loop behind the ear for both sides. 3?? Adjust and press down the nose clip on the respirator to fit to cover your nose and mouth. Check for any air leakagesIMPORTANT SAFETY DETAILS: ?This protective mask cannot generate oxygen and should not be used in hypoxic environments. ?Not intended as a replacement for gas masks and medical masks. Not for use if breathing is impeded or unsteady, or during sleep. ?If you are dizzy or if you are having difficulty breathing do not wear or use this mask. ?If you are a person with an asthmas condition, be careful wearing this mask. ?Masks are disposable and cannot be washed. ?Store in a dry and ventilated location 23ºF - 122ºF (-5ºC - 50ºC, relative humidity<80%).