The 3M™ Adflo™ Prefilter is a replacement particulate prefilter for the 3M™ Adflo™ Powered Air Purifying Respirator.The 3M Adflo Prefilter works in conjunction with the 3M Adflo Powered Air Purifying Respirator. It installs into the turbo filter cover, between the spark arrestor and the High-Efficiency (HE) Particulate Filter. The respirator offers powered respiratory protection for welders and features a lightweight, slim design. The 3M Adflo Powered Air Purifying Respirator is sold separately.