The DD 3x8 is a self-contained downdraft table from Diversitech. It is installed with an automatic reverse pulse self-cleaning system that allows an easy collection of dust, smoke and fumes from various applications above the perforated table top. It can be availed with a broad selection of application kits and customized fittings in order to adhere to OSHA standards of clean air. This table has large capacity paper-pleated filters that acquires an arrestance rating of 99.8% at 0.5 micron. A 2" deep metal mesh pre-filters is also available as an option. It also has a metal mesh pre-filters that are washable, and main filters that must be periodically replaced.