NIBCO 5818 Series ABS DWV Pipe Fitting, Plug, 4" NPT Male Plug for closing the end of a pipe or fitting Male National Pipe Taper (NPT) threads for connecting to a female threaded pipe ABS-DWV for chemical and corrosion resistance, performance under wide temperature ranges, and light weight for quick assembly Smooth interior finish for reduced friction and material buildup Meets specifications ASTM D2661 and D3311 for quality assurance