1. Skin-friendly and breathable fabric, comfortable to wear without sweating 2. The chin is designed with mesh ventilation, which is breathable and fits the skin 3. Holes are designed on both sides of the ear, which is comfortable to wear and does not affect sleep 4. Adjustable elastic design, can be adjusted freely according to personal preference 5. The edge is strong and wear-resistant, and the wiring is even and fine, suitable for long-term use 6. Material: SBR