Custom exhaust flange for use on Honda GX340 GX390 engines. Made with pride in Colorado, U.S.A. Center hole is sized for 1 1/4" tube. Flange is CNC cut from 1/4" steel to prevent warping. Stainless steel mounting hardware is included for installation. Great start for those that want to weld their own exhaust system for generators, go karts, mini bikes, or?