HCF/Pro-Grid Bulkhead and Diffuser O-Ring test-kit-type_Specialty Please note the wording is

Please note the wording is not 4 inches

The Big Horn is a classic dual post starting block featuring a 20 x 23 inch non-slip platform in your choice of colors

This shim set includes both plastic and phenolic material shims

This back-up ring goes inside the tank and is used on filters manufactured after 3/03

This is a replacement Pentair Sta-Rite

HCF/Pro-Grid Bulkhead and Diffuser O-Ring test-kit-type_Specialty Please note the wording isThis is a Hayward Diffuser O Ring replacement for HCF Series HCF7303C, SwimClear Cartridge Filters, and Pro Grid Vertical Grid DE Pool Filters. SX220Z2 is also a Bulkhead O Ring for Hayward MaxFlo VS Series pumps, MaxFlo XL, and MaxFlo II pumps.