Optimum Pool Technologies Universal Sleeve Nut Replacement for Hayward and Pentair Filter Clamp Fits Most Pentair and Hayward Filter Tanks Fits Hayward Filter Tanks : Super-Star Clear, Micro-Clear, Swim-Clear, Pro-Grid DEs Fits Pentair Filter Tanks: Clean & Clear Plus, FNS Plus, Quad DE Filter, Nautilus Plus (After 1999), SMBW 2000 Series, (Purex) SMBW 4000 Series Made in USA from solid machined brass Replace whenever existing nut is worn down or stripped