Product Description LDR 3 2X4 Black pipe nipple 2-inch x 4-Inch. 2-Inch x 4-Inch Black malleable pipe nipple. Hydrostatic tested and protected from corrosion with Varnish. 15 psi and not used for drinking water. From the Manufacturer LDR 300 2X4 Black Pipe Nipple 2-Inch X 4-Inch. 2-Inch X 4-Inch Black Malleable Pipe nipple. Hydrostatic tested and Protected from corrosion with varnish. 150 PSI and not used for drinking water.