we sell a full line of replacement air compressor filter elements for all major brand screw compressors such as atlas copco, kaeser, ir, elgi, cp, sullair etc with original type quality & most reasonable rates. From the major brands to the hard to find, including filters typically found on the air line, like coalescing filters (pre-filters) and particulate filters (after-filters), and filters that are on the compressor itself, like oil filters, air intake filters, and air/oil separators for rotary screw compressors. coalescing filter (pre-filter) elements coalescing filters capture oil, moisture and particles, binding them together until their mass is heavy enough for gravity to send this waste to a drain valve. A coalescer filter is often called a pre-filter because it is usually located prior to an air dryer to prevent oil and particulate from soiling the desiccant.