The Filtered Hopper will pick up items above it based on its filter. It can be filtered by putting an item in the top slot. If no item is in the filter slot then any item can pass. If any non-filtering item is placed in the slot only that item can pass.
When the Hopper receives mechanical power, it will output it’s content to the inventory below it be that be a block or an entity; if there is no block below it will simply drop the items on the ground.
If any of the follow items are in the slot only its specified types can pass.
- Ladders allows only Item types, no Blocks allowed.
- Trapdoors allows any Block through.
- Slats allow only flat items through, including paper, leather, strings and wool.
- Wicker will allow any dust, sand, seeds, or piles through, this can also be used to separate the Flint and Sand out of Gravel.
- Grates will only allow Items or Blocks with a max stack size of 1.
- Iron Bars will only allow Items or Blocks with a stack size greater than 1.
Soul Sand will only allow Souls to pass through it, including Soul Sand itself. Soul filled material will not pass through, yet the souls inside will be siphoned out and stored in the Hopper and refine the material. For example Ground Netherrack will add one soul to the Hopper and be refined into Hellfire Dust.
An unpowered Hopper can only sustain 7 souls on its own, if it receives any more bad things will occur.
These contained souls are used for the creation of Soul Urns. Additionally, it will also store experience orbs in the hopper, it can store up to 1000 experience; to retrieve it supply the hopper with mechanical power.