EasyPro EBD4A 4-Inch Heavy Duty Bottom Drain with Air Diffuser | Includes 4-Inch PVC Pipes | Ideal Airflow 0.5-1.5 CFM | Perfect for Koi Ponds, Water Gardens & Aquaculture Systems

Heavy duty, roto-molded design offers superior strength

Welded FPT threaded inlet eliminates the need for rubber coupling

Threaded center stand pipe securely attaches dome lid to base

Sixteen stainless screws securely attach liner ring to base with water tight seal

For use with 4″ schedule 40 PVC fittings and pipe, use 4″ male adapter (MA40) to connect to 4″ pipe, use reducing male adapter (RMA4030) to connect to 3″ pipe