This is a pressure vacuum breaker assembly. Production began in 1998. The body is made of bronze. In 2010 a 420XL was introduced which is made of lead free bronze. The test cocks are mounted on the ball valves not the body. The air inlet float utilizes a rubber fold not a spring to generate the air inlet loading. The float also contains a relief valve to protect against damage from freezing. The check is a modular design with a contained spring and replaceable check seat.
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.