Central unit and transceivers with corresponding operator console represent communication device in the railway line telephone system.

This equipment consists of:

• Central Units
  • Station Central Unit CU Tm 4304
  • Dispatching Central Control Unit DCU Tm 4304
    
• Selective Transceivers
  • Station Selective Tranceiver Tm 1902-5005/5032
  • Line Selective Tranceiver Tm 1902-5007/5033