|Engine Power (hp)||650|
|Speed Limit (km/h)||37|
|Standard Shell Penetration (mm)||115 - 155|
|Standard Shell Damage||480 - 800|
|Rate of Fire (rounds/min)||3.9|
Developed in 1945 on the basis of the IS-2 and IS-3 vehicles, under the supervision of Joseph Kotin. One of the distinctive features was the slope angle of armor plates. Passed trials successfully, but never entered service.