Always looking for ways to make the engine bay cleaner, lighter and easier to work with, STM designed these little, aluminum fittings to allow you to simply install -6AN lines and fittings for a catchcan or breather right onto your valve cover.
As the piece itself is a very tight fit, we would definitely recommend a bit of glue or epoxy to help hold it in place in the valve cover upon install.
Here's a comparison on the rear fitting vs the stock mess we previously had to run:
And the smaller fitting on the front, driver side on the valve cover.
