It specifically fits the Milwaukee 48228435 PACKOUT Compact Organiser.

The specific M12 Power File that this is designed for is model 2482-20, link is provide here: https://www.milwaukeetool.com/Products/2482-20

It should also fit the alternate model with the shorter arm, as that appears to utilise the exact same main body.
This is model number 2483-20.

https://www.milwaukeetool.com/Products/Power-Tools/Metalworking/Sanders-and-Polishers/

*Milwaukee PACKOUT and any tools pictured are not included, product for sale is the insert only!

This is a 3D printed product, layer lines and small artefacts may be visible, this does not affect the functionality of the product.

FREE standard shipping applies to orders within Australia based on the following conditions:

Spend $80+ on products
(*excluding tool inserts)

OR

$120+ when including tool inserts

All orders are sent using Australia Post