DescriptionLAB-500000003 This fume hood features a one-piece shell molded of polyethylene with a clear acrylic sash that slides on inside tracks. It can be set in an open, closed or intermediate position. When the front opening is in the closed position, the sash remains open slightly to facilitate continuous air flow. LAB-500000004 This fume hood is the same as LAB-500000003, shown above, but includes a flat internal baffle across the rear of the shell. The baffle slopes forward, leaving space beneath for air flow to sweep the deck, and space above in order to efficiently remove airborne vapors.