POWERTEC 75006 Inner Filter for POWERTEC AF4000 Keep your workshop with both clearer, breathable air and cleaner room surfaces Replacement parts for POWERTEC AF4000, Shop Fox W1830, Rikon 62-4000 and majority of air filtration systems High (Robust)dust holding capacity Filters airborne particles like dust and dirt as small as 1 micron Much more effective than fiberglass filters