Halex 1/2 in. Rigid Conduit Coupling 64005 - The Home Depot
4" x 2" NPT 304 Stainless Steel Reducer Coupling, Class 150
BMI USA Malleable Iron Pipe Coupling 2-COUPLING Hydraulic Supply Co.
Stainless Steel DN 12 Coupling For Spray Gun Socket G 1/2 inch Female Threads | Tameson.com
Sigma ProConnex 2-in Zinc-plated Steel Threaded Coupling Conduit Fittings in the Conduit Fittings department at Lowes.com
2" in Inch NPT 316 Stainless Steel Threaded Half Coupling Weld On Pipe Tube Bung Fitting SS for Home Brewing, Automotive, Industrial, Aerospace - Amazon.com
1/4" x 1/2" Stainless Steel Coupler - CPL-2550 | INDCO