The main difference between Flex and 1Size stickers on Nike hats is their size and purpose. Flex stickers are generally larger and are mainly used for decoration or event promotion, while 1Size stickers are relatively smaller and are mainly used to mark or promote specific sizes.

Specifically, Flex stickers are larger stickers with various colors. Different sizes correspond to different colors, such as yellow S, blue M, red L, green XL, white XXL, etc. This kind of sticker is mainly designed to decorate hats or promote events.

1Size stickers are relatively small and are mainly used to mark or promote specific sizes. The size and shape of this sticker can vary by brand and product, but is generally smaller than Flex stickers.

In short, the main difference between Flex and 1Size stickers on Nike hats is size and purpose. Flex stickers are larger and are mainly used for decoration or promotional activities, while 1Size stickers are relatively smaller and are mainly used to mark or promote specific sizes.