Refer to the specifications provided by the supplier to conduct random inspections on the dimensions and appearance of each part of the product: clear PET lenses, sponges, elastic straps, and fixed plastic buttons.
The most important points:
Test the anti-fog effect of PET lens, whether it is a double-sided anti-fog material
Sampling the PET lens of the protective mask for obvious scratches and creases.
Are there any certificates that you required