Ideal for most industrial and commercial cleaning applications, the ATEX Standard Cartridge Filter provides filtration of 10 microns @ minimum of 98% efficiency. Grounding strap provides electrical continuity for ATEX compliance. Fits all Guardair ATEX 55 and 30 Gallon Drum Vacuums. For finer filtration, substitute ATEX HEPA Cartridge Filter or ATEX ULPA Cartridge Filter.