The Hayward Union Adapter Assembly is no longer available
With this adapter you can convert the old style Hayward 2" Thin Threaded Union to a 1 1/2" threaded fitting which = 1 7/8" O.D. standard wet...
Half Union Fitting Complete Set... The Threaded side measures about 2 3/8" Inside and the Slip Glue end measures about 1 7/8" Inside Diameter...
Note: Although this measures very much like a 1 1/2"...