Adaptor.
First side:
Thread: 1/2" NPT
Thread Identification: O.D. (approx) 21mm (.826") x 14T.P.I.
Second side:
Thread: 9/16" JIC
Thread Identification: O.D. (approx) 14mm (9/16") x 18T.P.I.
Thread: 3/4" NPT
Thread Identification: O.D. (approx) 26.3mm (1.035") x 14T.P.I.
Thread: 3/4" JIC
Thread Identification: O.D. (approx) 19mm (3/4") x 16T.P.I.
Thread: 7/8" JIC
Thread Identification: O.D. (approx) 22mm (7/8") x 14T.P.I.