Check the listing for details. AquascapePRO? Dual Union Check Valve 2.0. Condition: New. Listed at 79.99 USD. AquascapePRO® Dual Union Check Valve 2.0 provides a professional pump and plumbing connection inside skimmer filter systems, as well as Pondless® Water Vaults. The heavy-duty, swing-style check valve flapper maximizes water flow through the valve when open, while preventing the backflow of water when the pump is shut off or during a power outage. Union connections on both both sides of the valve make pump and filter maintenance quick and easy without the use of tools. A set of innovative reversible fittings take the guesswork out of finding the right pump or filter fitting and allows the extension of valve height for taller filter applications, making this a truly universal check valve designed for water features.Connects the pump to water feature plumbingInnovative reversible fittings allow for universal applicationPrevents water backflow when the pump is not operatingDual-union, tool-free design makes maintenance quick and easyHeavy-duty swing-style check valve flapperHeight extendable for larger filters and pumps