Fritz X was a further development of the PC 1400 (Panzersprengbombe, Cylindrisch 1,400 kg)[Note 1] armour-piercing high-explosive bomb, itself bearing the nickname Fritz. It was a penetration weapon intended to be used against armored targets such as heavy cruisers and battleships. It was given a more aerodynamic nose, four stub wings, a box shaped tail unit, consisting of a roughly 12-sided annular set of fixed surfaces and a cruciform tail with thick surfaces within the annulus, which contained the Fritz X's aerodynamic controls.