It took us several years to pull the trigger on this fantastic tool, but I highly recommend it. The reverse flush valve allows you to rinse and clean out your holding tanks before putting your camper in storage for the winter. A few weeks ago we were on a full hookup site and could not BELIEVE how well this device flushed out our tanks. Pair it with this handy dandy hose (small and easy to transport) for cleaning your tanks with ease 🙂 It is also on sale for Prime Day!!!