If you put on some aftermarket wheels, you probably have a gap to the stock bump stop.  These are much larger and will keep your tire from rattling around. This is a very easy mod for your Jeep JL.  This is a 2 piece kit. It takes around 30 minutes to install.  Best of all you can get it on Amazon for less than $32 bucks.

get it on amazon

REVIEW OVERVIEW
Looks Cool
Better than Stock
Easy to Install
Easy on the Wallet