When you purchase this key, you get to choose which of the 7 items you want. This is not luck based.

In the server, you can choose one of these:

• Cow Spawner

• Spider Spawner

• Zombie Pigman Spawner

• Skeleton Spawner

• Blaze Spawner

• Creeper Spawner

• Iron Golem Spawner

The spawner can continuously spawn mobs for you, which makes it easier to farm resources and XP without having to search for them.