Tool gizmo shells are used in the Invention skill to generate perks for use on augmentable tools. They may be manufactured at an inventor's workbench.
Discovering this device requires level 22 Invention. Success in creating the blueprints earns 1,541 Invention experience.
Using a tool gizmo shell opens an interface allowing you to combine different materials to generate perks. This creates a tool gizmo, which can then be used on an augmented tool to give it the perks.
Ancient tool gizmo shells may also be made at an inventor's workbench, creating ancient tool gizmos. These function similarly to the tool gizmos in adding perks to tools.