Fleece dust filter bag design – works with vac090-series dust extractors as a preliminary filter and a secure way to capture debris and dust Helps with OSHA compliance – Moves users toward compliance with the OSHA respirable crystalline silica dust regulation when combined with the vac090-series dust extractor and HEPA filter Preliminary filter – captures most of the debris and dust and increases the life of the main filter Dependable port cover – securely closes opening of the filter bag and keeps the dust and debris inside during the disposal process Bosch PRO+GUARD – provides HEPA filtration as part of an end-to-end dust-protection system