NIBCO 4801 Series PVC DWV Pipe Fitting, Coupling, 3" Hub Coupling for connecting two pipes with the same diameter in a straight run Hub ends for connecting to male unthreaded pipes or fittings PVC-DWV for corrosion resistance, high strength, and less weight than fittings made from metal Smooth interior finish for reduced friction and material buildup Meets specifications ASTM D2665 and D3311 for quality assurance