Here you can learn how to obtain and switch Cosmetics in Diablo Immortal.
Cosmetics are used to customize the hero' looks, beyond changing the currently equipped items (at a vendor or during events) They allow you to switch your current look of an outfit or weapon, regardless of what items the character has currently equipped.
To do this, open your Inventory and select Cosmetics from the bottom bar. You'll see your Cosmetics on the right side. Of course, you can replace your equipped outfit or take it off at any time to return to "default". Our chosen Cosmetics are of course visible to other players. To buy Cosmetics, you need Eternal Orbs (premium currency)