Value Collection - Malleable Iron Pipe Coupling: 3/4″ Fitting - 36990356 - MSC Industrial Supply
Pipe Fittings - Steel Couplings 1/4" x 1/4"
Everbilt 1/2 in. x 1/4 in. FIP Brass Reducing Coupling Fitting 802169 - The Home Depot
Horiznext npt 1/2 (means the inner diameter of the thread is 3/4 inch) cast female taper threaded pipe coupling, stainless steel 304 coupler for mush tun cooler and shower hose, 2 pcs - Amazon.com
Black Pipe Fittings - 1-1/2 NPT Right & Left Coupling, 150# UL/FM