Amazon.com: French Drain Man 4" Corrugated Pipe Adapter (4” Corrugated to 4" PVC) PVC Fittings, PVC Couplings, Corrugated to PVC, Connect Corrugated Pipe to Pop Up Emitter : Industrial & Scientific
Spring Loaded Pop Up Drain Emitter w/ Elbow & Adapter 3&4 in
3″ Corrugated Adapter for 5″ Polylok | Drainage Kits