Stainless Steel 316 Cast Pipe Fitting, Union, Class 150, 1/8" NPT Female Union for connecting and extending two male pipes Female National Pipe Taper (NPT) threads on both ends for connecting two male threaded pipes Made from stainless steel 316 for strength Higher corrosion resistance than stainless steel 304 Meets standards ANSI B1.20.1 and ISO 49 for quality assurance