What are Companion Units?

Companion units allow you to improve the functions of your Multi-Tool. To install one, hover over an empty slot in your Multi-Tool's menu and press X to "Install Technology."

You'll see a list of all of the Companion Units you know how to build, along with the resources needed for each. The list of Companion Units will quickly get overwhelming and difficult to parse. You can filter the list by Multi-Tool function by clicking on the Icons across the top of the submenu — these correspond to All, Laser, Projectile, Grenade and Scan.

Where to find Companion Units

While you will find plenty of blueprints for Companion Units during your travels — in Damaged Machinery and in wall units inside of structures — you can't add any more inventory slots to your Multi-Tool.

Where to find new Multi-Tools

Happily, you can find new and better Multi-Tools to buy. Keep an eye on the walls inside buildings and space stations for a rectangular box that opens when you approach.

Interacting with the Multi-Tool on display pulls up its basic information and price and gives you the option to compare it to your current one — for a price.

While you don't have to worry about storing resources in your Multi-Tool's inventory slots, more slots are better. More Multi-Tool slots allow you to install more Companion Units, making your Multi-Tool faster and more efficient at gathering resources.

There's no option to transfer inventory or Companion Units between Multi-Tools, so be prepared to devote resources to rebuilding any that don't come pre-installed.

Would you like to know more?

No Man's Sky is a largely solitary experience, but that doesn't mean you have to travel the universe alone. This is but one small section of Polygon's No Man's Sky guide.

Be sure to check out the rest, where you can learn all about your ship, your Multi-Tool and Companion Units and even get answers to some of the biggest questions about No Man's Sky. We also have a guide to No Man's Sky's resources that'll teach you the difference between Oxides and Silicates and No Man's Sky's various elements.

If you're just looking for a quick reference guide to locations, like where you can save and trade — we've got you covered — too.