Hopper Transfers

Rules

Slots	5.
Speed	1 item every 0.4 seconds (8 game ticks). In the same step it can push 1 item out and take 1 item in.
Redstone	A Hopper that receives a redstone signal does not push, pull or pick up items. Other Hoppers can still put items into it and take items out of it.
Order	In each step the Hopper first pushes an item into the container it points at, then pulls from the container above it or picks up loose items.
Pushing out	Moves 1 item from its first slot whose item fits into the container it points at.
Pulling in	Takes 1 item from the first slot of the container above that it is allowed to take from and has room for.
Loose items	A dropped item stack lying above the Hopper is picked up whole if there is room, not 1 item at a time.
Hopper chains	A completely empty Hopper that is handed an item by another Hopper waits 8 or 7 game ticks before its own next move, depending on which of the two acted first in that game tick.
Stacking	An item joins a stack only if it is exactly the same item, including name, enchantments and other properties. Otherwise it needs an empty slot.