Replaceable paper filter bag for Festool CT 22 Dust Extractor. Filter bag captures and contains 5.3 gallons of dust and debris, helping you work cleaner and more efficiently. The cleanest and fastest way to contain dust and dispose of it completely. Festool filter bags act as the primary, or first stage filter, trapping particles down to 5 microns in size. WIth a double layer of filtration made of tear resistant material, and a cap to seal it for disposal, filter bags are a must for optimum performance and convenience. Filter bags prevent dust from reaching the main filter of the dust extractor, thus greatly extending the life of the main filter and dust extractor