●Billet Fuel Cell Cap Flush Mount Perfect for build your own fuel cell tank,replacing missing or damaged mounting caps,these replacement mounting cap assemblies may fit other 12 bolt cells. ●Cap OD: 5.5" (139.5mm); Cap Opening: 2.25" (57mm) ●Body Material: CNC Billet 6061-T6 Aluminum Alloy ●Color: Silver Anodized ●Body Material: CNC Billet 6061-T6 Aluminum Alloy