This single use N95 Respirator has a 95% filter efficiency level. It is effective against particulate aerosols free of oil; time use restrictions may apply. These lightweight, contour fit respirators are maintenance free, have 2 elastic straps for a comfortable and efficient fit, and allow easy breathing and speaking while in use. The exhalation valve located on the front of each mask efficiently releases uncomfortable moist air from inside the mask, reducing heat, moisture, and fogging. Valve masks packaged 10 per box (10 boxes per case).