Features: Kit Conversion: This kit is designed to retro-fit for 800M4-QT to freeze resistant 800M4-FR. Protect the pressure vacuum breaker from freezing conditions, which can cause damage to the system and lead to potential water leakage. Added Protection: The 0887726 freeze-resistant kit mitigates the risk when water freezes inside the backflow. It prevents expands which resulting in increased pressure and cracks, providing added protection against cold temperatures. Good Sealing: .