ANTISIPHON AIR VENT TRAP FITS BEHIND WALL OR UNDER CABINET 1.5″ SCREW IN ABS

Automatic Anti-Siphon Trap Vent.
Air automatically enters drain line to prevent siphonage- and then seal closed after drainage to prevent escape of sewer gases.
NSF approved.
For secondary venting of sinks- lavatories- tub/showers- washing machines.
Not for use in venting water closets.
Made of black ABS.
Bulk.