Custom Fit: This retrofit kit is specifically designed for 1" 800M4 series pressure vacuum breaker (PVB) backflow preventer, converting your 800M4-QT into a freeze- 800M4-FR model. Enhanced Functionality: This retrofit kit repairs leaks or malfunctions in your pressure vacuum breaker and adds freeze resistance, ensuring optimal performance in colder climates. Easy Installation: Designed for user-friendly installation, this kit allows you to easily convert your device by yourself, saving you time and service costs. Health-Conscious: The kit helps prevent the reverse of polluted water into your potable water supply, ensuring safe water usage. This retrofit kit is an essential upgrade for your 800M4 series pressure vacuum breaker, enhancing its functionality and durability in freezing conditions. It is easy to install, allowing users to perform the conversion without professional assistance. While it provides freeze resistance, it is important to drain and winterize your device in extreme cold to maintain its effectiveness. Color: Black Material: plastic Package Contents: 1*Backflow Convert Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.