BrassCraft BC9441 BZ Dishwasher Air Gap with Brass Cap, 5/8" O.D. Tube x 7/8" O.D. Tube Plastic Body in Oil Rubbed Bronze Ensures waste water is not siphoned back into the appliance's fresh water supply Provides an alternate route for discarded water in the event that the drain hose becomes blocked Required by many local plumbing codes