Filtered system has interior depth of 23 in., accommodating large micro and analytical balances. Clean-Sweep airfoil allows air to sweep work surface, while upper containment sash foil bleeds air into enclosure to direct contaminants away from user's breathing zone. Tempered safety-glass sash, sides, and top are fire, scratch, and corrosion resistant. Bag in/bag out system allows HEPA filter to be safely removed and replaced. Enclosures are available in 2, 3, and 4 ft widths.