--- title: Inventory Tester id: irregular_implements:inventory_tester related_items: [irregular_implements:inventory_tester] type: block --- The **Inventory Tester** must be placed on an inventory, and stores an item in itself. It will emit a redstone signal if the inventory is capable of accepting that item. It also checks the *side* of the inventory it's attached to. If placed on top of a Furnace, it will only work if the Furnace can accept the item into its top. Because of that, you may want to also use the [Inventory Rerouter](@irregular_implements:inventory_rerouter). You can invert it in its GUI, so it emits a signal when the inventory *can't* accept the item.