Hayward Filter Manual Air Relief Assembly, Fits ProGrid, SwimClear, DEX420MAR2

DEX2420MAR2 Hayward Manual Air Relief Assembly Used On Hayward SwimClear Cartridge and ProGrid DE Filters By Hayward. Does Not Fit Hayward MicroClear DE or Super Star Clear Cartridge Filters. Includes Gauge, O-rings and Air Relief Assy. Locks In Place with 1/2 Turn Into Filter Top.