The BK Mueller, and ProLine vacuum breaker kit.

The BK Mueller ProLine 888-576HC Vacuum Breaker Repair Kit is designed to work with ProLine Series Anti-Siphon Frost Free Sillcocks. Here are the key details:

• Function: The vacuum breaker prevents waste water from entering your fresh water system.
• Installation: It fits into the top opening of the valve and is easily installed.
• Compatibility: Specifically designed for ProLine Series Anti-Siphon Frost Free Sillcocks.
• Construction:
  • Material: Made of POM (Polyoxymethylene).
  • Chrome-Plated metal Cap: Protects the anti-siphon mechanism.
  • Plastic Anti-Siphon: Prevents backflow into the valve.