NDS 1243 Combo 4" by 3" Outlet, Black Connects NDS catch basins to multiple sized piping Designed to fit 9-Inch, 12-Inch, 18-Inch and 24-Inch catch basins New Locking Outlet snaps on to most 3-Inch and 4-Inch corrugated pipe Made from quality material for optimum performance New locking outlet snaps on to most 3-Inch and 4-Inch corrugated pipe