The U-flak boats had greatly increased anti-aircraft firepower, U-441 was fitted with additional gun platforms forward and aft of the conning tower, which served as a base for two four-barrelled Flakvierling 20 mm flak guns and one 3.7 cm weapon, as well as a number of MG 42 machine guns.
The feeding mechanism resembles the one used in the MAG machine gun (a simplified version of the MG 42's feed system) operated with a feed arm driven by the motion of the striker sleeve.