Fernco AAV Bottom-Outlet Air Admittance Valve Kit, Under Sink Vent, Helps Reduce Odor and Gurgling, 1-1/2 in Tubular

The Fernco AAVKIT-2 bottom-outlet aav kit is a complete, diy-friendly solution for improving under-sink drain performance when the drain line comes up from the floor. The bottom-outlet layout keeps the aav neatly positioned above the drain connection, adding venting support without opening walls or running a new vent line where permitted.
The aav opens to admit air when needed to help maintain the trap seal and reduce gurgling and slow draining, then closes to help block sewer gas odors. Designed for common residential under-sink applications including bathroom lavatories, kitchen sinks, bar or prep sinks, and utility or laundry sinks. The kit connects to standard 1-1/2" tubular under-sink plumbing, installs vertically within 15° of plumb, and must remain accessible for inspection or replacement with a minimum 2" clearance for airflow and maintenance. Temperature rated -4°f to 140°f. Always confirm local plumbing codes and installation requirements before installation.