TREND STEALTHSM STEALTH MASK SMALL MEDIUM Offers less breathing resistance Less clogging pressure & inward leakage Approval P3R APF20 x WEL Protects the user against airborne particles oil aerosols mist welds & fumes Twin HEPAC pleat encapsulated design filter provides 9999 filtration of airborne particles & aerosols at 03 micron & above Exhalation valve on bottom of face piece ensuring no exhalation fumes steam or fog of any glassesvisors Protective grill covers 100 of filter surface Grill protects filter from moisture & particulates ensuring it performs better in clogging pressure & filtration efficiency To read more about this product on our blog pclick here