Our new target model had **FIVE** external valves. Galley, sink, sewer on one side of hoop, fresh water drain and van washer on the other. I'd have hoses and 'Y's all over the place. Tie the two grays together and run them down a 3-inch drain using this connector. I now have a hose for her and one for the RV washing machine which I can hook up to another drain tap or "Y" at will. country if ever needed.