3M OH&ESD has introduced the new 3M Half Facepiece Respirators, 7500 Series Ultimate Reusable. This respirator features the 3M Cool Flow Exhalation Valve for easier breathing and reduced moisture buildup. Along with a dual-mode head harness, the respirator employs an advanced, soft silicone material to ease tension on the user's face.3M OH&ESD, St. Paul, MN.