Converts Dry Box into HEPA filtered storage cabinet. Mounts directly to existing dry box with minor alterations. Optional on new boxes. Variable speed controller maintains positive pressure in box. HEPA filter 99.99% efficient 0.3 microns and large. Dust Guard prefilters 35% efficient ASHRAE. 115V, 1 phase 60 HZ. 25-250 CFM fully adjustable. Acrylic construction. 14"W x 14"D x 16"H, with a 12" x 12" x 3" HEPA filter. The dry box filter system can be quoted to fit dry boxes RD-18 to RD-60 units.