Billet Oil CapOur engine caps & handles are machined from 6061-T6 billet aluminum, and feature a brushed & textured surface with clear anodized finish. All caps, with exception of our radiator cap cover and TJ power steering cap cover, are complete replacement caps. The radiator cap cover and power steering cap cover, fit over your existing radiator and power steering caps. Together with our battery hold down clamp, these caps will give your engine a complete custom look.