The Suction Tube is an "upward hopper": it pulls items from containers in up to five directions - below it, and its four horizontal sides - and pushes them, one at a time, into a container placed directly above it.

Like a vanilla Hopper, it moves at most one item every 8 ticks, and only works if a container is placed directly above it. When more than one connected side has matching items available, the Suction Tube picks between them at random so no side is starved.

Right-click the block to open its Filter configuration screen.

Each of the five input sides (Down, North, East, South, West) has its own row of 4 filter slots, arranged in a cross around the tube's icon in the GUI.

Filter slots are ghost slots: placing an item into a filter slot sets a template - "only accept this kind of item" - for that side. It does not consume the item from your inventory or cursor. Clicking a filled filter slot clears the template again; you never lose or gain real items while editing filters.

If a side has no filter set, it accepts any item. If one or more filters are set on a side, only items matching one of them will be pulled from that side.

The screen also shows, for each side, whether a container is currently connected (its icon is displayed), whether that side is locked by a Redstone signal, and the current input signal strength.

Locking a side (Input)

Place a Comparator facing into the Suction Tube on one of its four horizontal sides to disable item pickup from that side. Any signal strength greater than 0 locks that side - the exact strength doesn't matter for locking.

• North, East, South and West each have their own dedicated Comparator connection.
• The bottom (Down) side has no Comparator connection of its own. When one or more horizontal Comparators are attached, Down follows their combined lock state; with no horizontal Comparators attached, Down is always unlocked.

Signal Output

Whenever the Suction Tube successfully transfers an item, it emits a Redstone pulse for one tick. A Comparator facing away from the tube reads a signal strength that tells you which side the item was pulled from:

• 1 - North
• 2 - East
• 4 - South
• 8 - West
• 5 - Down (fixed value)

Without a Comparator, any other Redstone-reading block (e.g. a Redstone Lamp or Repeater) simply sees "powered" (signal strength 15) for that one tick.

Both the digital and the analog output can be turned off independently using Game Rules.

Crafted from Lapis Lazuli, a Piston, a Hopper, Iron Ingots and Redstone:

• Row 1: Lapis Lazuli - Piston - Lapis Lazuli
• Row 2: Lapis Lazuli - Hopper - Lapis Lazuli
• Row 3: Iron Ingot - Redstone - Iron Ingot

The Suction Tube has a small set of configuration options, all available as Game Rules (per world).

Game Rules

• /gamerule wunderreich:suctiontube_redstone_power_when_sucking [true|false]
  Emit a level 15 Redstone signal for one tick whenever the Suction Tube transfers an item.
• /gamerule wunderreich:suctiontube_analog_redstone_output_for_suction [true|false]
  Emit an analog Redstone signal (readable with a Comparator) that identifies which side an item was pulled from.