3M Large Half Facepiece Reusable Respirator 7503/37083(AAD), Respiratory Protection, Large Advanced silicone material for increased comfort and greater durability Proprietary 3M CoolFlow valve helps makes breathing easier Dual-mode head harness adjusts easily for either standard or drop-down mode Exhalation valve cover directs exhaled breath and moisture downward to reduce fogging Color coded to indicate size (small, medium or large) for easy identification