Direct head-hardened railway rails type R65 category DT350 for general interchange applications. Direct head-hardened railway rails type R65 for special applications:

• DT350SS category: rails designed for speeds up to 250 km/h, intended for application primarily in the high speed combined
  traffic lines. Enhanced-geometry rails;
• DT350NN category: rails for ultra low temperature applications primarily intended for operation in subzero climatic regions;
• DT370IK category: rails of high wear resistance and contact fatigue endurance for applications in 600-m and shorter railway
  curves;
• DT400IK category: rails of enhanced wear resistance and contact fatigue strength for applications in tangent tracks for speeds
  up to 200 km/hour and curves with no tonnage restrictions;
• DT350VS category: rails for high-speed passenger traffic.