Orbit MRB-400/350 4 to 3-1/2 Inch Trade Size, Malleable Iron Reducing BushingsOrbit MRB 400 350 MRB 400 350 Product Description Orbit Industries Malleable Iron Reducing Bushings are used to decrease the thread size of female hubs to accommodate smaller sizes of male threaded conduit or hubs. Malleable Iron construction maintains mechanical protection for the raceway. Features: Malleable iron construction ensures mechanical protection for the raceway Electroplated Zinc for added corrosion protection About Orbit: Orbit