NIBCO 4801-7 Series PVC DWV Pipe Fitting, Adapter, 1-1/2" Hub x Slip Joint Adapter for connecting pipes or fittings of different types Hub opening on one end and slip joint connection on the other for connecting two unthreaded pipes 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