NDS 3 in. x 4 in. PVC DWV to Sewer and Drain Adapter is designed to connect 3 in. drain, waste and vent (DWV) pipe to 4 in. sewage and drainage (S and D) pipe in the installation of non-pressurized drainage and sewer piping systems. PVC construction is durable, lightweight, economical and resistant to corrosion and chemicals. Connects 4 in. sewer and drain pipe to 3 in. DWV Schedule 40 pipe.