Medium Aquafalls Waterfall Filter with Matala Filter PadsAquaFalls Filters have an inlet hole on each side of the filter (except the mini AquaFalls). Use the one that's most convenient for your incoming water and simply plug the other hole with plug (included) or buy a ball valve and use the second hole as a drain. Details: Easy to install, simply bolt lip to filter and you're done no foaming rock lip into place AquaFalls Filters are buried into the ground making them easy to hide Ships by motor freight