NIOSH certified. The #7940 P100 Particulate Filter Disks have an efficiency level of 99.97% or greater against both oil and non-oil based particulate aerosols. Use the 7920 Piggyback Adapter with the 7940 P100 Particulate Filter Disk with any 7000 Series gas/vapor cartridges. The P100 Particulate Filters are suitable for most welding applications. 100% PVC-Free®. P100 Particulate Filter Disk is lighter than traditional Filter Cartridge. Piggyback with Moldex® gas/vapor cartridges or use standalone filter. Wider field of vision because of low profile. Fiberglass-free filters. No plastic casing to throw away.