The Plumber's Choice 4 in. x 3 in. Grooved Reducer Fitting, Ductile Iron, Joins Pipes in Wet and Dry Systems, Full Flow in Orange H3327 - The Home Depot
China Lowest Price for FM UL CE Approved Ductile Iron Fittings Reducing Threaded and Grooved Tee factory and suppliers | BESTOP
VSH Shurjoint groove reducer coupling + ring 76.1 x 60.3mm, red, 349580 | Wholesale Van Walraven
2.5" Grooved Coupling Pipe Clamp - North Ridge Fire Equipment
Profit Grooved concentric reducer
Ductile Iron Grooved Pipe Fittings 4''x 2 1/2'' Thread Concentric Reducer with FM/UL Approval - China Pipe Fittings, Grooved Fittings | Made-in-China.com