Capable of capturing the most minute particles, ATEX ULPA (Ultra Low Penetration Air) Cartridge Filter meets the highest industry standards for air filtration by providing filtration of 0.1 microns @ minimum of 99.999% efficiency. Ideal for working with allergens, mold, pollen, superfine powders, etc. Grounding strap provides electrical continuity for ATEX compliance. Cloth Pre-Filter Bag provides extra stage of filtration extending the life of the cartridge filter. Fits Guardair ATEX 55 and 30 Gallon Drum Vacuums.