The Diamond Plated Loot Chest includes a set of 20 Trading cards with one-time use SHiFT codes (that unlock Legendary items in game) and do not expire.
To redeem, at the Borderlands 2 Main Menu select Extras then SHiFT code.
The item will appear in the back of, and be the same level as, the first character loaded after code redemption.
Please note: in order to receive these items at level 51 or higher, you must load your character in Ultimate Vault Hunter Mode.
If you feel that the code redeemed is incorrect, please provide Submit a Ticket with your SHiFT e-mail address and images of the items in-game and the list of rewards in the SHiFT Menu.