The Mörser Karl was a tracked artillery piece armed with a 54cm or 60cm mortar for bombarding heavily fortified positions. Initially the mortars were armed with 60cm mortars (040) but in 1942 54cm barrels (041) were produced to increase its effective range. The kit also includes a Munitionspanzer IV which was a Pz Kpfw IV Ausf F converted with a crane for lifting the enormous shells.