slam cap

i was looking at kennedy website and saw the ultem slam caps, i was kinda interested in what they are used for? is it just for looks? or do they give better flavor?

I have been wanting a neat little low profile RDA to put on my tiny IPV D4. I already have a standard Tugboat v2 and love the nice open deck but it's a couple of years old and the center pin is starting to get torn up. I would just get a slam cap and some replacement parts if Flawless still...