20 DFU (Drainage Fixture Unit) capacity. Complies to ASSE (American Society of Safety Engineers) Standard 1050 and 1051 for use a a secondary vent. One size approved to handle up to 3″ vent pipe. Opens and closes as needed by building’s plumbing system, 1-1/2 – 2″. No. 39016: Size: 1-1/2″ to 2″, Use on Diameter Branches: Up to 3″, Material: PVC, Pkg Qty: 1, Package Type: Box No. 39017: Size: 1-1/2″ to 2″, Use on Diameter Branches: Up to 3″, Material: PVC, Pkg Qty: 1
