Product DescriptionThis is the replacement cap for 5.5hp and 6.5hp minibikes, mopeds, ATVs… even generators. This cap fits the tanks along with other 37mm notched metal gas tanks.Cap description:Cap width: 72mm [2.8″]Cap inside width from tab to tab: 47mm [1.86″] outsideCylinder diameter: 37mm [1.47″] without tabsSingle hole in center of cylinderTop of metal cap is solidRubber gasket for good seal of tank/capTabs insert into notches on tank and turn to lock cap into place.6500/168F 16521/168FFits the BT200X, CT200U and CT200U-EX mini bikes.