Not kilos, but pounds.
"The main armament was the 380 mm Raketen-Werfer 61 L/5.4, a breech-loading rocket launcher, which fired short-range, rocket-propelled projectiles. These projectiles were roughly 1.5 metres (59 in) in length and could either contain a high explosive charge of 125 kilograms (280 lb) or a shaped charge for use against fortifications, which could penetrate up to 2.5 metres (98 in) of reinforced concrete. The stated range of the former was 5,650 metres (6,180 yd). The weight of the complete rounds was 345 to 351 kilograms (760–770 lb). A normal charge first accelerated the projectile to 45 metres per second (150 ft/s), the 40 kilograms (88 lb) rocket charge then boosted this to about 250 metres per second (820 ft/s).
The design of the rocket launcher caused some problems, as the hot rocket exhaust could not be vented into the fighting compartment but neither could the barrel withstand the pressure if the gasses were not vented. Therefore a ring of ventilation shafts were put around the barrel which channeled the exhaust and gave the weapon somewhat of a pepperbox appearance.
Because of the bulkiness of the ammunition, only 14 rounds could be carried, of which one was already loaded, with another in the loading tray. The rest were carried in two storage racks. To help with the loading of ammunition into the vehicle, a loading crane was fitted at the rear of the superstructure, next to the loading hatch. Even then, the entire five man crew had to help with the loading."
