The vehicle was developed at the beginning of the 1930s by the Design Bureau of the Kirov Experimental Machine Building Plant No. 185 (Leningrad). The project based on the T-26 light tank was designed for supporting mechanized units. Three prototypes with 76, 122, and 152 mm guns were produced. The variant with the 122 mm gun saw mass production. A total of 30 vehicles were supplied to the army. The project was discontinued in 1937.
The technical characteristics shown are for the Siege mode
Characteristics are specified for a vehicle with crew members trained to 100%.