If a player does not sign a contract with a sneaker manufacturer, he will ask his favorite manufacturer to provide him with sneakers, and the manufacturer will provide him with the sneakers that the player wants for free. Because playing in the NBA is the best publicity for sneakers, the manufacturer is happy to provide sneakers.

The NBA does not require the brand of sneakers, only the color: only black or white sneakers are allowed. Otherwise, you will be fined.