The monstrous German Self-Propelled Mortar Karl-Gerat 040/041 was one of the largest mobile land-based weapons deployed in World War II. Designed to destroy heavily fortified bunkers or fortresses, six operational vehicles were produced, supported by Panzer IV munitionschlepper tanks.

Trumpeter's massive Karl-Gerat is sharply molded in tan plastic and includes a nice fret of photo-etched detail parts, two finely crafted aluminum shells, and the option of building the initial or late chassis versions. Tracks are vinyl belt-style, and are nicely detailed. Two sets of vinyl tracks are included, one with and one without hollow guide horns, among other differences, to depict the early- and late-style tracks. Mortar barrel features accurate rifling. Includes eight German artillery crew figures. Decals are provided for vehicles nicknamed Loki, Eva, Adam, Thor, and Ziu, but instructions are given only for Eva (initial chassis) and Loki (late chassis).