2 ½" x 2 ½"S Waterway Union Assembly

The Waterway hot tub pump union 400-5990 has threads referenced as 2.5-inch with an actual inside diameter of 3-11/16-inch and a 2-inch slip end. The slip end of this union is designed to fit over a fitting with a 2-inch spigot end or schedule 40 PVC pipe or flex hose referenced as 2-inch with an actual outside diameter of 2-3/8-inch. It's important to note that in the pool and hot tub industry, plumbing dimensions are referred to as nominal sizes rather than actual sizes. See the diagram for details of inside measurements. Details: Waterway P/N: 400-5990 Brand: Waterway Plastics Threads: 2.5-inch, (Actual ID 3-11/16") Connection: 2-inch Slip Colour: White Material: PVC Includes O-ring Pump Union Sizes Measure the Inside Diameter "ID" of your current "CLOSED" split nut or regular nut. If it measures: 2-7/16" then you need a 1-1/2" 3-1/16" then you need a 2" 3-11/16" then you need a 2-1/2"