Oatey 74158 PVC Pipe Base General Purpose Cleanout with 6-Inch NI Cover, 4-Inch Designed for use in finished areas where moderate to heavy traffic is expected Designed to provide easy, reliable access to drain systems PVC cleanouts designed to comply with ASTM D2665 ABS cleanouts designed to comply with ASTM D2661 Barrel threads are 3-1/2-Inch IPS