VehiclesIS-1ИС-1ИС-1FamilyISClassTankNative classHeavy tankChangesHull with a stepped cast front 60–120 mm and an opening driver's visor, shared by the IS-1 and the IS-2 Model 1943. Crew 4, V-2IS 520 hp.Produced107Service193719381939194019411942194319441945Soviet Union · Eastern FrontFeb 1944 – Oct 1944Modifications 2193719381939194019411942194319441945IS-1 (D-5T)107Feb 1944 – Oct 1944IS-2 Model 1943Based on this vehicle 2193719381939194019411942194319441945ISU (cast nose)≈ Mar 1944 – May 1945Jun 1944 – Oct 1944Aug 1945 – Aug 1945ISU (welded nose)