Created by Rheinmetall-Borsig, it is a very heavy and complicated weapon system, with its barrel and base alone weighing 220 kg.

This automatic 5 cm mortar could fire a maximum of 120 bombs a minute, and was electrically operated with manual backup.

In this way enemy soldiers seeking cover from direct fire would be flushed out into the open, so that the machine guns could engage them.

It required a significant number of rounds to have effect on troops in prone positions and seeking cover.

[2]: 225  Where possible the entire construction was to be buried underground, leaving just the flat armoured opening on the roof to fire through.

The automatic feeder for the mortar required a three-phase electricity supply to power the lift, otherwise ammunition had to be passed up.