Russian 57mm ZIS-2
The M1941 ZIS-2 was an efficient dual purpose anti-tank/field gun that was just about to enter service when the Germans invaded the Soviet Union. The later M1943 model used the split-trail carriage of the 1942 model 76mm field gun, ZIS-3. Armour penetration was 140mm at 500m and in this form the gun served out the war and for many years afterwards. Maximum range with HE was 5200m. Examples captured by the Germans were designated 5.7cm Pak 208(r).
Photos show optional crew set, Accessory Pak A25.