The bezel D, built in 1860-63, secured the northern flank of the fortress Küstrin together with the older right wing bezel.
The bezel is shaped like a pentagonal semicircular route and is protected by a double moat. Another special feature is a shelter for the gun teams in the right wing. There were two ammunition niches for standby ammunition, which could be locked with steel doors.
How long the military use lasted is not known, however the bezel D remained part of the military planning. In 1928 the reduit was blown up to form a flatter silhouette. The gun emplacements should continue to be used as artillery positions.
In the defensive battles in 1945, the bezel D was heavily contested and was defended until all ammunition was fired. During the fighting, the ammunition magazine was destroyed and the shelter was badly damaged. After 1945, the bezel D was occupied by troops of the Soviet Army, who built accommodation and a snail-shaped observation post in the left Glacis. Parts of the left wall with the debris from the left powder magazine were used to build a dam over the moat, since the wooden drawbridge was destroyed in the war. Remains of the drawbridge can be seen at low tide. The bezel D is privately owned and can only be viewed with the permission of the owner.