This key can be used to open: FEVER CRATE DESPERADO CRATE GAMESCOM INVITATIONAL CRATE Land on strategic locations, loot weapons and supplies, and survive to become the last team standing across various, diverse Battlegrounds. Squad up and join the Battlegrounds for the original Battle Royale experience that only PUBG: BATTLEGROUNDS can offer.

The key has to be redeemed in-game in Store -> Redeem Gift Code section.