The Pentair R172221Z O-Ring Vent Valve is a specialized component designed to enhance the functionality and reliability of pool and spa systems. This O-Ring Vent Valve features a 3/8-inch inside diameter and is made from durable rubber, offering a robust and flexible sealing solution. The primary purpose of this valve is to provide a reliable seal while allowing for the controlled ven... https://www.usapoolshop.com/r172221z-pentair-o-ring-vent-valve