Nuts & Bolts Volume 37 covers the early versions of the Jadgpanzer IV, also called "Guderian duck". This "tank" first designed 1942 on an order of the Heereswaffenamt to VOMAG and first introduced in 1944 was basically a new successor to the Sturmgeschütz. There was a considerable effort by the General der Artillerie for the retention of the designation "Sturmgeschütz". Guderian battled and won his case for the issuing of the tanks to the Panzerjäger units of the Panzer-Divisions. Despite the inexperienced Panzerjäger units the Jagdpanzer IV became a very worthy adversary against the Allies Armored opposition. This volume includes the early versions of Panzerjäger IV chassis No. V2 to the leichte Panzerjäger IV with the 7.5 cm Pak 39 L/48. As the authors formulated the production of this volume it became apparent that the historical information we obtained could only be done justice if they produced two volumes on one of the most important German tank of the Second World War. Together with Volume 38, which is devoted to the VOMAG and ALKETT versions with the 7.5 cm Pak 42 L/70 and on the Einheitsfahrgestell, all versions of this formidable vehicle will be included to the standard of information that readers have become used to.