The SLK wheels are a collectible item used to customize a player's vehicle. They provide no advantages while in use and are purely cosmetic. They are classified as very rare.
There is a random chance to obtain them from the Overdrive Crate, or by trading in five rare items from the same crate. They can also be traded between players.
A special version of these wheels called SLK-VL was offered in the PlayStation Plus Pack during Season 2.