Spears 435-SR Series PVC Pipe Fitting, Adapter, Schedule 40, 1/2" Socket x 1/2" Steel Reinforced NPT Female Adapter for connecting pipes or fittings of different types Socket connection on one end and steel-reinforced female NPT threads on the other for connecting two pipes with different ends PVC for corrosion resistance, high strength, and less weight than fittings made from metal Stainless steel collar for PVC thread reinforcement Meets NSF/ANSI 61 Annex G, NSF/ANSI 372 for quality assurance