Fits 3" & 4" Corrugated pipe, 3" & 4" Sewer and Drain Pipe, 4" SCH. 40 Pipe, 4" Triple Wall Pipe. Locking Outlet snaps onto most 3 and 4 Inch Corrugated Pipe. One end fits into 9", 12", 18" and 24" Catch Basin Series or #930, #1230, #1830, and #2410 adapters. Locking outlet is used with the 24" Catch Basin Series and also requires #2410.