The IS-4 turret, with powered traverse, was noted by Nicholas Moran to be larger and roomier than the IS-3 turret, allowing for more ammunition for the coaxial machine gun. The IS-4 may have had an intercom system on the back of the turret to allow mounted infantry to talk with the tank crew.
The IS-4 turret's size and spaciousness were noted by Nicholas Moran as being greater than that of the IS-3 turret, allowing for more ammunition storage in the coaxial machine gun. The possibility of an intercom system on the back of the turret to facilitate communication between the tank crew and mounted infantry is also mentioned.