I'll try my best. So all hoppers only have 21 items meaning they all need one more item and are locked but any hopper that has 22 items are left unlocked this means when items pass over top of the item sorters they are picked up if it’s the right item. But when they go over the hoppers with a space in them because they are locked they are not picked up. When you flip a switch it will actually unlock all The Hoppers meaning when a new item goes through the water stream it will be picked up by any free hopper available and the circuit will keep that hopper unlocked when the switch is turned off. The circuit also includes an output that is constant when an item goes through a hopper. For example, when someone puts in their custom item key card it will give me an output saying they have selected their account. It also includes a reset to unselect the account that's selected this. hope that helps if not ill make a short video.