Studor Mini-Vent used for Plumbing Drain Ventilation. Studor Mini-Vents are "IT", when you just can't "hit the roof!" Studor MiniVents - Air Admittance Valves fit 1-1/2 in. & 2 in. pipes.

Maxi-Vent® by Studor® fits piping systems of 3" (80mm) & 4" (100mm) diameters, ABS or PVC pipe. The Studor® Maxi-Vent® can vent up to 500 Drainage Fixture Units (DFUs). Studor Air Admittance Valve (AAV) replaces plumbing vent systems that penetrate roofs. Allows air to enter plumbing systems to equalize pressure when water drains, maintaining "water trap seals" & prevents sewer gas in buildings.

STUDOR® MAXI-CAP (20398) is a spun aluminum cap that is specifically designed to protect MAXI-VENTS® from damaging UV rays and temperature extremes and other threats when installed outdoors. MAXI-CAP includes two pieces of double-sided adhesive and is paintable.