This is an air inlet head that was attached to the downside of the second check of a double check assembly. This would make the double check assembly a two check pressure vacuum breaker. It utilizes the air inlet design of the 2" SMR Model 711. It was used by the Beeco Company on their double check assemblies from approximately 1960-1975.
Common repair parts are a very small subset of the 10,000 plus items BAVCO stocks.
Please feel free to contact us direct at 800-458-3492 for pricing on items not listed
or backflow prevention devices.