The Hayward SX200Z7 Filter Tank O-Ring is a critical component designed for maintaining the integrity and efficiency of pool and spa filter systems. This O-ring, crafted from durable rubber, measures 7.0 inches in size with an inside diameter of 20.4 inches and an outside diameter of 21 inches. Its primary function is to create a watertight seal between the filter tank and the lid, pr... https://www.usapoolshop.com/sx200z7-hayward-filter-tank-o-ring