Customizable inine electrical connection box

This is a customisable electrical connection box, ideally suited to hold a terminal block or even some circuitry (as the box dimensions are configurable). It has an in-cable grommet and an out-cable grommet with configurable hole diameters.

You will also need:
2x (approximately) 2.5mm screws

Hints:
If you use 0 for grommet length, it will remove the grommets altogether.
It you use 0 for either of the cable values, it will close those holes; so you can produce a box with a single cable hole if you wish.