[1] A decision was made in 1970 to replace the Soviet 100/56 B-34 single 100 mm semi-enclosed gun mount.
By June 1973, the first batch was completed and two were installed onboard frigates for test and evaluation.
The first of the family, this gun was fully automatic and controlled by Type 343 radar.
However, being the first fully automatic gun and the first indigenously developed gun at the same time, the Chinese was not confident enough on the design, and thus incorporated manual backup systems.
[2] As a result, the total weight and size of the gun mount was reduced.