A tank destroyer from the series of heavy vehicles under the K-91 designation. Development of this series was started in the spring of 1949 by the Design Bureau of the Army Engineering Committee under the supervision of A. F. Kravtsev. The plan was to mount the 12-cylinder opposed-piston supercharger diesel engine. Mounting brackets with ski-shaped supports were used as support rollers. The project was discontinued at the blueprint stage in December 1949.