ventedor nonvented gas cap?

[mrzen]

I spent sometime and couldn't find an answer. I want to replace my gas cap with a Stant locking gas cap. There is an option for a locking vented and a non vented cap for my 2004 explorer. Which one, vented or non vented? Why are there both options for the same model? Thanks!

 

[ncranchero]

Did you look it up on the actual Stant site? I don't see questions about vent/non-vent there only cap color. Check it out.
STANT