From the designer:
This is a custom insert that I have designed to fit your Milwaukee Packout to store your Dewalt Barrel Jigsaw and accompanying kit. It specifically fits the Milwaukee 48228435 PACKOUT Compact Organiser.
The specific Dewalt Barrel Jigsaw that this is designed for is model DCS335, link is provide here: https://www.dewalt.com.au/product/dcs335n-xj/18v-xr-brushless-body-grip-jigsaw-bare-unit