Waterway gasket designed for hot tub heater or pump unions. Designed to go inside a 2" union and is classified as a 2-inch gasket. The Waterway 711-4030 is flat on one side and then has a raised o-ring on the other. Typically comes in a transparent material, Balboa's original ones be black or white. It is best practice to always change both gaskets on the heater tailpiece or the intake and discharge of the pump.
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