Vented gas cap?

What type of fitting is that?
Looks perfect for the job but uncommon. I saw this post recently somewhere else on here.

One thing I don’t quite understand, the vented cap will release pressure and let it out, the evap system also absorbs the escaping fumes. I’m looking to allow air into the tank, it has to get in so the fuel can get out. Does the evap system allow for this? If not what does? This simple tube vent system will.
Do you need to plug the tube when the car is stored inside?