This check valve is made of white schedule 40 PVC for corrosion resistance, high strength, and less weight than fittings made from metal. It is compatible with schedule 40 PVC (polyvinyl chloride) pipes and fittings. Its full flow design allows for insignificant flow loss at the swing check, so no spring is needed. It has 1-1/2" slip connectors at both ends to connect to pipes with a smooth bore for enhanced flow and has a maximum pressure rating of 150 psi.