Anvil 8700157954, Steel Pipe Fitting, Coupling, 1/4" NPT Female, Black Finish: Amazon.com: Tools & Home Improvement
1/2" FIP Stainless Steel Pipe Coupling at Menards®
Sigma ProConnex 1/2-in Zinc-plated Steel Threaded Coupling Conduit Fittings in the Conduit Fittings department at Lowes.com
Southland 1-1/2 in. Galvanized Malleable Iron FPT x FPT Coupling Fitting 511-207HN - 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