Milwaukee Twins Skull Gas Cap Set For Harley Milwaukee Twins Skull Gas Cap Set has an eerie 3-D effect with a black background and raised chrome skull. The cap has been formed from steel with ABS plastic threads. A ratchet action allows to position the skulls to your liking. Features: Chrome skull on a black background Steel cap with ABS plastic threads Ratchet action allows you to keeps skull aligned Matching Milwaukee Twins Derby and Points covers available