高性能带阀防护口罩 WILLSON 5211M/L • 专业的呼气阀设计,尽可能降低呼吸阻力迅速排除湿气 • FFP2的过滤效率(带呼气阀) • With an innovative design to the new exhalation valve which provide the minimal exhalation resistance and a faster evacuation of the moist exhaled air • FFP2 filtering rate (with valve)