Help with straps

[rootbeer7]

Apologies for trying to hijack Ruud's earlier strap thread. I thought better to start my own.
With my Pam came 2 additional straps, a dark brown leather and a black leather as a small gift from DavidSW.
I've noticed that all but the black leather one has metal tubes in the end that attaches to the watch. Both additional straps are Panerai. Do I need to take the metal tubes out of one I'm not using, or does it not matter?
Thanks fellas.