Test Plug Item Test Plug Type Wing Nut Drain Line Diameter 4 Inch Material ABS Plastic Operation Type Mechanical Allowable Test Back Pressure 5 PSI Air Allowable Pressure Head 40 Foot Water Inclusions Features Steel Plated Screw, Zinc Nut, Neoprene Gasket Application DWV Pipe Testing Pipe Diameter 3.78 to 4.06 Inch