The Rinnai 22mm Connection & Isolation Valve Pack is a must-have for enhancing the functionality and safety of your Rinnai water heating systems. Designed with precision and compatibility in mind, this valve pack seamlessly integrates with the Rinnai 55, 1300 & 1600 models, ensuring a perfect fit and effortless installation. For use with 22mm copper tube on the hot & cold water connections. The gas connection is also 22mm.