NDS 1241 Universal Round Adapter for Basins, 4-Inch Diameter Basin adapters are specifically designed to connect NDS catch basins to multiple sized piping intended for the evacuation of drainage water Universal adapters will connect to corrugated, sewer and drain and Sch.40 pipe in sizes ranging from 3" to 12" Designed to fit 9", 12", 18" and 24" catch basins Fits 3" and 4", corrugated pipe, sewer and drain pipe, SCH. 40 pipe and triple wall pipe Designed for maximum durability and drainage