QMP804AG is one of our custom designed air gap faucets with a sleek designed Arc Spout that is typically used with under the sink RO units. This faucet comes with our Washer Set, QMP522AG, for easy instillation. This exceptionally well-made, stylish faucet provides extra room underneath the spout and insures your filtered water does not mix with tap water or drain water. As a leading manufacturer, our 800 series faucet fixtures have unparalleled quality and a uniquely innovative design that features an exclusive ceramic disc handle. The purpose of the air gap faucet is to provide a siphon break to assure that drain water can€™t flow backward from the household drain system into the RO unit.