The Pentair 87300400Z Tank Body O-Ring is a crucial component for maintaining optimal performance and efficiency in various Pentair pool and spa filter systems. This rubber O-ring is designed to create a watertight seal between the upper and lower halves of the filter tank, preventing leaks and ensuring proper filtration. With a thickness of 1/4 inch, an inside diameter of 9 inches, a... https://www.usapoolshop.com/87300400z-pentair-tank-body-o-ring