Oatey 39220 AAV, 2"" &ndash; 3"", 2-Inch,Oatey,39220" /> Complies to ASSE Standard 1050 and 1051 For use as a secondary vent One size approved to handle up to 4" vent pipe Opens/closes as needed by building's plumbing system Sweet Spot? technology opens at -0.01 psi and seals at 0 psi and above Air admittance valve For use as a secondary vent Opens and closes as needed by building's plumbing system Use as an air inlet source One size approved to handle up to 4-Inch vent pipe For use as a secondary vent One size approved to handle up to 4&#034; vent pipe Opens/closes as needed by building&#039;s plumbing system For use as a secondary vent One size approved to handle up to 4&#034; vent pipe Opens/closes as needed by building&#039;s plumbing system For use as a secondary vent One size approved to handle up to 3&#034; vent pipe Opens/closes as needed by building&#039;s plumbing system New, smaller size: 4-1/2&#034; x 5-3/4&#034; High-impact polystyrene construction Accommodates 6 or 20 DFU AAVs with 1-1/2&#034; or 2&#034; adapters