A total of 713 of the Sd.Kfz. 165 "Hummel" (Bumble Bee) were built between 1942 & 1945. It was a combination of the 15 cm heavy field howitzer 18/1 & the weapon-carrier III/IV. The fighting compartment was only protected on all sides leaving the top open to facilitate the aiming of the cannon. Most of the Hummels were used on the Eastern Front, where they saw their first action in 1943 in Operation "Citadel". In addition to Russia, nearly all the large tank divisions stationed in France & Italy were equipped w/Hummel batteries. If necessary the Hummel could also be used as a tank destroyer. The main feature of the late version is its wider fighting compartment with a front section for the driver & wireless operator.