Box Item I can't open
You may want to look those up on the trading post before doing anything else. You won’t be disappointed. Unless you already destroyed them.
Do not destroy them. Instead, enter PvP with them, and they will be used automatically.
These chests used to contain rare skins for weapons and armor, and were only good in PvP. The functionality was changed after the creation of the Wardrobe. Now the contents will be stored in your (otherwise unaccessible) PvP Locker and then duplicated over to your Wardrobe. At worst, you’ll get nothing new; on the other hand, you can get some things that are no longer available in-game, or would require you to shell out a lot of gold to unlock.
I haven’t destroyed them yet. Thanks. Off to PvP land I go.