1-1/4" Merchant Steel Coupling, Sch. 40 Galvanized Pipe Fitting, Class 150 - Hi-Line Inc.
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
Ace A+ Series Extruded Fire Hose Couplings — Action Coupling
Tube to Tube Coupling – Hydromax
Tube Fittings Manufacturers and Suppliers in the USA
Pipe Fitting by Types - Types of Pipe Fittings, Thepipefittings.com