The spherical cut-off turret allows it to maintain a good equivalent protection capability after reducing the armor thickness. The original design of the tank, which is similar to the commander's observation tower of German tanks, is made into an embedded design, and other changes and designs make the weight slightly reduced. The main gun uses the same ZIS-6 tank gun as the KV-4 and is slightly shortened, and a composite armor skirt plate made of manganese steel / alumina ceramic is installed on the side.However, at that time, the country's aluminum and some rare metal industries were weak and still relied on imports, the cost of this scheme was extremely high, but the performance was good, and about 400 units were mass-produced from 1952 to 1958.