Halex 1/2 in. Rigid Conduit Coupling 64005 - 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
Aluminum, 1/2 in x 1/2 in Fitting Pipe Size, Straight Coupling - 60PV88|ZUSA-PF-9382 - Grainger
Amazon.com: FangKingNo 5pcs 1.5 Inch White PVC Female Adapter Pipe Fittings (Slip to Female Thread) Coupling with Female Hose Thread Schedule 40 (1 1/2") 5 of pack : Industrial & Scientific
Amazon.com : 5 Pack - Orbit 1/2 Inch Female Thread PVC Coupling for Sprinkler Pipe : Patio, Lawn & Garden
Southland 1/2 in. Black Malleable Iron FPT x FPT Coupling Fitting 521-203HN - The Home Depot