1Double layer silicone pad, dynamic fit, reduce accidental air leakage, larger activity space. 2Wider view, no forehead support design, better line of sight. 3The headband is easy to remove, simple operation, convenient to fix. 4Silicone material, soft texture, easy to clean and disassemble. 5Multi-directional rotating elbow, more air vents to disperse airflow and reduce noise.