This Gas Cap is CNC Machined from billet aluminum with a knurled edge with a satin/raw finish (gas cap has an O.D. of 1.75" and I.D. Fill of 1.25") Kit comes complete with a gas cap and aluminum weld-in bung with a nice lip on it to sit correctly on top of your Oil or Gas tank. Gas/oil cap is not vented, but can be with a simple hole drilled through the cap. Made completely and proudly in the U.S.A.!