Why 2 felt seals?

[PareosWC]

We're almost finished with buttoning up the front knuckles on the WC52. While looking at the old seals- the felt , felt retainer, and spring are common sense use and easily understood. However, what is throwing me for a loop is why a rebuild kit for (1) knuckle comes with (2) of the smaller, half-mooned felt retainers?

I see that that the metal retainer holds one felt in place where the cork and metal retainer are split, but where does the second one go??