The Dual Union Check Valve 2.0 from Aquascape reliably prevents backflow in ponds and water features, ensuring a secure pump and plumbing connection within skimmers and Pondless® Waterfall Vaults. The heavy-duty, swing-style check valve flapper is constructed for durability and optimizes water flow through the open valve, prohibiting backflow when the pump is off or during an outage. Innovative reversible fittings make it a cinch to locate the appropriate pump or filter attachment - simply turn the fitting to the desired orientation. Unions are found on both sides of the valve, making pump and filter maintenance fast and tool-free. This check valve is compatible with a wide range of filters, allowing the valve's height to be easily extended when needed.