The 3M™ Reusable Respirator Exhalation Valve Filter is designed to mount on the valve cover of 3M™ Half Facepiece Reusable Respirators 6000 Series. This filter is designed to help filter the exhaled breath of the respirator wearer and provides source control when worn with 3M™ Half Facepiece Reusable Respirators 6000 Series.