The EMPI dual purpose oil filler & breather includes a system of internal baffles that seperate the oil from the hot air then returns the oil back into the engine. It mounts upright on the alternator stand making for easy oil filling and was designed to look like part of the engine. The billet aluminum filler cap seals with an o-ring seal and the button head allen top screws. Vent your valve covers crankcase and air cleaners. Comes with attaching nut o-rings gaskets and instructionsOil Breather & Fill Tower for All Aircooled VW