The Hayward CX120AA Filter Head with Vent Valve, replacement component designed for use in a variety of pool and spa filtration systems. This filter head is required to keep your filtration system running smoothly and effectively, resulting in clean water. It has a 1-1/2" NPT connection size, making it suitable for a wide range of systems. The NPT connection type ensures a secure and ... https://www.usapoolshop.com/cx120aa-hayward-filter-head-w-vent-valve