This is the same high performance respirator as our no. SWMK910-N95, but with an exhalation valve to make it easier to breathe through in hot or humid work conditions. Our unique exhalation valve offers maximum inhalation protection while providing minimal exhalation resistance. This feature and all those of our standard no. SWMK910-N95 combine to offer the proper fit and durability. Special featured welding elastic which is an alternative choice for head-straps.