The 3M 4277 Maintenance Free Respirator is a lightweight ready-to-use half mask designed for effective and comfortable protection against organic vapours and particulate hazards.The 3M 4277 Maintenance Free Respirator is a lightweight ready-to-use half mask designed for effective and comfortable protection against organic vapour and particulate hazards.This respirator requires no parts assembly or maintenance and is designed for protection against organic vapour inorganic acid gas and particulate hazards.This is for up to 10 x Workplace Exposure Limit (or 1000ppm whichever is lower) for organic inorganic and acid gas and up to 20 x Workplace Exposure Limit for particulates.It features two large bonded carbon filters for low breathing resistance and soft non-allergenic face piece material with textured face seal.This 4277 reusable half mask has been designed with a low profile to allow a better peripheral vision it has an adjustable head cradle and easy to fasten neck straps.To improve comfort the exhalation valve has been centrally positioned which allows for an effective removal of heat and moisture.These respirators can be reused until damaged the particulate filters become clogged the gas filters become saturated or after one month.FeaturesReady to use requires no assemblyProtects against organic vapours inorganic/acid gases & particulatesLightweight and comfortableAllows for good peripheral visionAdjustable head cradle and easy to fasten neck strapsSoft non-allergenic material with a textured face sealCentrally positioned exhalation valve