Dura 897-040 4" SCH 80 PVC Slip x Slip Union are pipe fitting connectors designed to connect two pipes together without the need for sealants or couplings. Using PVC connectors allows for easy assembly and disassembly without the need for specialized tools. Dura Plastics PVC is made from high quality materials and is perfect for any pool or spa. This item is not recommended for use in compressed air or gas systems.