Sure Vent, Air Admittance Valve, Advanced Sealing Technology With 1-1/2" - 2" PVC Adapter, Solvent Welds To 1-1/2" & 2" With Supplied Adapter & Threads Into 2" Female Iron Pipe Adapter, Tested To Comply For DWV To NSF Standard 14 ASSE 1050 & ASSE/ANSI 1051 A&B With On Going Quality Control For Plastic Components & Standard Compliance, Sure Vent Exceeds The ASSE 1050/51 Standard's Positive Pressure Rating.