# HUB Upgrade 4

> Canonical source: [HUB Upgrade 4](https://satisfactorybase.com/wiki/schematics/hub-upgrade-4)
> Language: en

## Properties

- Entity type: Milestone
- Tier: 0
- Inventory slots: +3

## Unlock cost

- [Iron Plate](/wiki/items/iron-plate): 75
- [Cable](/wiki/items/cable): 20
- [Concrete](/wiki/items/concrete): 10

## Prerequisites

- [HUB Upgrade 3](/wiki/schematics/hub-upgrade-3)

## Unlocked buildings

- [Conveyor Pole](/wiki/buildings/conveyor-pole)
- [Conveyor Belt Mk.1](/wiki/buildings/conveyor-belt-mk-1)

## Technical Details

- Class name: Schematic_Tutorial3_C
- Native class: FGSchematic
- Asset path: /Game/FactoryGame/Schematics/Tutorial/Schematic_Tutorial3