Regularly changing a pleated filter is an inexpensive way to help keep dust collectors running more efficiently. Most replacement pleated filters on RX4CleanAir.com have a MERV 8 efficiency rating. Search by dimension to more readily find the PN needed for your industrial air cleaner / dust collector. Pleated filters are sometimes referred to as pre-filters or Stage 1 filters. For oily or mist applications, see the Metal Mesh Filter section of RX4CleanAir or contact a representative.