1. The housing is Three floors Structure (outer shell / inner shell / cover integral)

2. The actual sound insulation decibel can go 30DB the above. (values that can be reached by layer 3)

3. The earmuffs are Not at all Any glue glued. (no possibility of any toxic substances)

4. The product is all EU Environmental testing Certified. (All materials are made of new materials, without any recycled materials)