This is a custom insert designed by Jonah Pope Design to fit your Milwaukee Packout to store your M12 Gen 3 Drill & Impact. It specifically fits the Milwaukee 48228435 PACKOUT Compact Organiser.
The specific M12 Drill and Impact models that this is designed for is model 3404-20 & 3453-20, links are provided here:
https://www.milwaukeetool.com/Products/3403-20
https://www.milwaukeetool.com/3453-20
Note for those using the belt hook:
There are two variations of this design that are provided for you to pick from. One is the standard version (which is seen in the photos above) and the other is a mirrored version. The standard version accommodates your tool if you have your belt hook attached on the same side as what is seen in the photos above (the left side when holding the tool)