Located on the passenger side in the engine compartment you have your main air conditioning lines. Each of the main lines has a capped valve (fill point), that has a black plastic cap on the valve opening. (The one line goes to the Receiver/Dryer and the other line goes to the condenser up front).
Both of these new chrome-plated caps are vented like the original black plastic cap that they slip over.
A nice cosmetic touch even for those that may not like a lot of chrome under the hood.