Mossberg 500 Sling cap recommendations

[xDoodles]

Hey guys, I have a Mossberg 500 and already bought a sling with Uncle Mike's swivels. My question is, should I just buy the sling stud to fill the hole on my Mossberg's magazine cap or should I buy Uncle Mike's cap adapter? The cap adapter comes with extra swivels is why I'm having a dilemma as I am trying to save money on a budget.

I need some input. Thanks!