Received my order from Camping World today. It is an RV Hydro Flush that cleans the holding tank, pipe, valve and hose. It allows you to safely flush out your sewer hose and holding tank after dumping by sending a blast of fresh water into the waste tank to remove remaining debris. Anti-siphon valve installs on fresh water faucet to prevent contamination of fresh water system. The clear plastic helps you see when tank and hose are flushed clean. The cost = $19.99.