This Spears clear coupling pipe fitting is made of schedule 40 PVC and has socket end connections. This coupling fitting connects two pipes with the same diameter going in the same direction to extend a straight run. This coupling has female socket connections for sliding over the ends of unthreaded male pipes or fittings. The socket ends connect to pipes with a smooth bore for enhanced flow. This schedule 40 (standard wall) fitting is made of PVC (polyvinyl chloride) for corrosion resistance, high strength, and less weight than fittings made from metal. It is compatible with schedule 40 PVC pipes and fittings. PVC can be connected to other materials such as steel, copper, or cast iron using transition fittings. This fitting provides superior flow to metal because of its smooth interior finish, which reduces friction and inhibits buildup of materials. This fitting complies with National Sanitation Foundation International (NSF)/American National Standards Institute (ANSI) 61 Annex G, NSF/ANSI 372, and conforms with lead content requirements for âlead freeâ plumbing as defined by California, Vermont, Maryland, and Louisiana state laws and the U.S. Safe Drinking Water Act due to take effect January 2014. This coupling pipe fitting is suitable for use in cold-water pressure distribution systems including irrigation, pool and spa, potable water, and chilled water applications.