Tuning Weird FX Impact shroud oring arrangement.

I was replacing the oring in the back of my shroud. I took it out, looks like a 14x2. Dug through a kit I got from Yen but couldn’t find a match. Looked back in the shroud and saw what I thought was a shaved off piece of the one I took out. Took it out and it’s a 17x1. Why would FX put 2 orings in one groove? I don’t have either of these in the Impact oring kit I got from Yen. Anybody else run into this?
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