The Panther is a German medium tank deployed during World War II on the Eastern and Western Fronts in Europe from mid-1943 to the war's end in 1945. An improved version, the Panther Ausf. A, entered production in August 1943. This received improvements from the Panther Ausf. D, including a better turret with a new commander's cupola and increased turret traverse speed. More improvements began to have an effect on the combat-ready rate of the tanks deployed on the Eastern Front, which increased from 37 percent in February, to 50 percent in April, and 78 percent by the end of May 1944. In later Ausf. A and all Ausf. G models (starting in late November-early December 1943), a ball mount in the glacis plate with a K.Z.F.2 machine gun sight was installed for the hull machine gun and also received the Nahverteidigungswaffe.