Introduced in the 1950s, Soviet S-60 57mm anti-aircraft artillery (AAA) were the division-level air-defense system of the Soviet Union, before being replaced by SA-6 GAINFUL/2K12 surface-to-air missiles. The primary version, of which the Type 59 was a Chinese copy, was a towed autocannon, firing from 4-round clip magazines. A comparable Western clip-fed autocannon was the Bofors 40mm. The S-60 had a secondary ground-fire capability, especially against tanks.
When on its towing carriage, it depended on visual guidance, but could be radar-controlled when taken off the carriage and linked a fire director (e.g. PUAZO-5 or PUAZO-6) and radar (e.g. SON-4, SON-9, FIRE CAN or FLAP WHEEL). There was also a dual mount attached to a tank chassis, which, while more mobile, could not be radar controlled. Range is 4km with visual guidance and 6km with radar guidance.
The S-60 has been used by over 40 countries, and was the most important AAA piece in North Vietnam during the Vietnam War.