https://www.gamespot.com/articles/pubg-adding-weapon-skin-system-region-locking-in-n/1100-6457710/

Another update is on the way soon to PlayerUnknown's Battlegrounds on PC. Developer PUBG Corp. has deployed a new build of the game to the test server, giving players a chance to try out a new weapon skin system and other features before they roll out for the live game soon.

The weapon skin system, as you can gather from its name, gives players the ability to customize their weapons' appearance. Players will be able to acquire different skins for their guns through new types of loot boxes, which can then be applied to the weapons through the Customization menu.