If you're flushing your RV black and gray-water tanks or cleaning out a tote tank, then you have to use a separate hose so that you don't risk cross-contamination with a drinking water hose. The Camco RhinoFlex 25' Gray-Water Hose has a 5/8" internal diameter, is made of durable PVC, and is bright orange so that you don't accidentally mix it up with your drinking water hoses. The ends are compatible with standard garden hose threads.• Ideal for flushing RV black water, gray water, or tote tanks• Keeps contaminants separate from your drinking water hose or garden hose• Compatible with standard garden hose threads• Made of durable PVC Ends are compatible with standard garden hose threads Made of durable PVC 25' long hose with 5/8"" inner diameter | Camco RhinoFlex Black-Water Clean-Out Hose, 25' x 5/8" ID in Orange