This direct replacement Clutch Reservoir Cap has the improvement of a bellows as part of the gasket/seal. The bellows is similar in concept to the ones found on many brake master cylinder reservoirs. It rides on the top of the fluid and reduces splashing of the clutch fluid. The bellows also provides a barrier to squirting fluid when the clutch is released quickly. The net result is that it completely stops all “drool” on the outside of the clutch reservoir.
The OEM cap (shown in one of the photos) has no protection from splashing fluid onto the center vent of the cap. This is why the OEM cap tends to get really messy.