Valterra W01-4300 Flushing Hose - 1/2" x 25', Gray The gray color easily distinguishes it from white drinking water hose. The gray color easily distinguishes it from white drinking water hose. Designed for non-drinking water usage including flushing devices that clean waste tanks or use as a gray water drainage hose. 1/2" I.D. x 25' Length Color: Gray