The FT1's Nanofiber-composite diaphragm is waterproof coated. The FT1 has passed the reliability test conducted by FIIO Laboratory, which includes not only high temperature, high humidity, low temperature, high and low temperature shock, etc., but also more than daily life environment test, and the data and listening sensation are all within the standard range. It is safe to use. In order to prolong the product's working life, it should be put into the storage bag when it is not used for a long time.