ZiS-2 (Russian: ЗиС-2) was a Soviet 57-mm anti-tank gun used during World War II. It is a semi-automatic gun with vertical block breech. When firing the block opens and closes automatically, the loader only has to put a round into the receiver. Due to this feature the rate of fire can reach 25 rounds per minute. The split-trail carriage with gunshield was shared with the ZiS-3 divisional gun. The carriage has coil spring suspension, which allows towing with a speed of up to 50 km/h (31 mph) on highways, 30 km/h (19 mph) on unpaved roads and 10 km/h (6.2 mph) off-road. The gun can also be attached to a limber and towed by a team of six horses. ZiS-2s are equipped with PP1–2 panoramic sight.