Simplify drainage and waste venting with the STUDOR® REDI-VENT™ Air Admittance Valve. The unique design of the STUDOR REDI-VENT provides ventilation to prevent the loss of water seals in traps without the need for expensive roof penetration and vent piping. For Venting single fixtures, kitchen sinks and bathroom groups including back to back applications up to 20 DFU. Exclusive vermin protection system. Expands architectural design limits. Compact design for tight applications. Fits 1 1/2" and 2" pipe sizes. Limited lifetime warranty for replacement of defective valves. Residential or Commercial Use. ANSI/ASSE 1051, NSF 14 and Warnock Hersey.