Features P100 FILTER DISKS P100 Particulate filter disks are lighter than traditional filter cartridges. Wider field of vision because of low profile design. Encased in plastic for durability and rough handling Fits under welding helmets. Easy twist on/twist off, bayonet style attachment. Efficiency level of 99.97% or greater against both oil and non-oil based particulate aerosols. Piggyback the 7940 filter disk with any Moldex gas/vapor cartridge using the 7920 Piggyback adaptor. Meets heat and flame resistance in accordance with ANSI/ISEA 110-2009 Section 7.11.1. 100% PVC-Free for a greener alternative.