Coupling | Insert Barb x Insert Barb x Insert Barb | Insert Barb x MIP | Threaded x Threaded | Threaded | 1-1/2" x 1" | 1-1/2" x 3/4" | 1-1/4" x 1-1/4" | 1" x 3/8" | 2" x 1/2" | 3/4" x 1/2" | 8" - 3" x