Willson® N99 SAF-T-FIT® Plus N1139 Large Premium Disposable Particulate Respirator With Blue Nose Ridge comes with an exhalation valve that eases breathing and offers exceptional comfort during extended wear. It provides 99% efficiency against oil-free particulates and is excellent for general industrial, welding, soldering, metal cutting, metal pouring, torch cutting and other high temperature or dusty operations. Respirator is latex-free and meets NIOSH 42CFR84 standard. Respirator offers N99 protection combined with a full sealing flange for the best fit and protection available. Respirator is sold as 10 per box.