Bronze Vented Loop – 2″ HoseFeatures:Allows air to enter to break siphon, but does not permit air and odors to escape! Cap is threaded 1/2″ NPT to accept a barb fitting if you wish to vent overboard.Overboard venting is required if PVL or HVL series is used in an exhaust system.HVL and PVL series vented loops assure clog-free anti-siphon protection for sanitation or engine exhaust systems. The oversized vent valve can easily be removed for inspection or cleaning without tools.Mount Hardware is included. Specifications:Type: Vented LoopsBox Dimensions: 7″H x 7″W x 7″L WT: 4.05 lbsUPC: 742985172807