The ten After Filter-Exhauster combinations are designed to capture dust particles as small as 0.3 microns using cotton sateen cloth filter tubes as the filter media. Equipped with top mounted Exhausters which pull contaminated air to the filter tubes, releasing clean air into the work area, where permitted, or into the atmosphere. They are completely weatherproofed for outdoor applications, when equipped with vent cover. Recommended Exhauster sizes and specifications are to be found in the chart below. Electrically operated, manually controlled shakers are standard on the FT 40S, FT 140S, FT 64S, and FT 164S series, Optional on FT 24S Series.