This is a great product! Definitely cut doing partial water changes to my aquarium in half. All you have to do is hook one end to your sink and the other end will serve as the vacuum to take water and debris out of your tank. Once you're done taking water out, just twist the faucet adaptor thing and it will send water back to your aquarium. Also there is a control valve if you want to slowly put water in or out. Just add a dechlorinator and you are all set to go. Definitely a back saver!!!