The 105 mm P.T. verst. (Panzerturm : armoured turret - versträkt : re-inforced), officially named '10cm T.K. (verst.)', were specifically designed by Krupp on the base of short-recoil 105 mm guns, mounted in a Schumann-type cupola, for the fortresses. The gun tube was re-inforced to give it a higher resistance to shelling and shrapnells.

Main specifications :

• Weight in firing position : 82000 kg
• Calibre : 105 mm
• Tube length : 35 calibres
• Projectile weight : 20.2 kg
• Initial velocity : 512 m/s
• Maximum range : 10120 m