Moldex® AirWave Particulate Respirator Mask Industrial N100 with Valve Not Rated Adjustable Head Strap Medium / Large (1200993_CS) 30/CSExclusive easy breath wave design; less resistance and better breathability Contouring foam face seal applies less pressure for added comfort Soft cloth SmartStrap allows you to adjust for a customized fit SmartStrap allows the respirator to hang around the neck when not in use Dura Mesh shell resists collapsing in heat and humidity Molded nose bridge seals easily without a metal noseband FlexFit design moves easily with your face and stays in place