Coupling | 3/4in | Male National Pipe Thread (MNPT) | Socket Weld x Threaded | Threaded x Threaded | Threaded | 1-1/4" x 1-1/4" | 1-1/4" x 3/4" | 1/2" x 1/2" | 2-1/2" x 1" | 2" x 1" | 3/8" x 1/8"