In the early days of production, it was produced at Hyundai Precision's Changwon plant, but it was produced at the same plant after Hyundai Precision, Daewoo Heavy Industries, and Hanjin Heavy Industries, the nation's top three railway vehicle manufacturers, were integrated into KOROS on July 1, 1999.

It has been improved from the existing TGIS to form a network with a transmission speed of 2.5 Mbps, and especially for the first time, it has reverse and braking command functions, further enhancing vehicle responsiveness and unifying the control function of service devices suitable for single-seater rides.

The seat adopted a matte stainless steel sheet, and the fire alarm and room emergency intercom were reinforced.

Since 2010, flame retardant mottled seats have been installed only in the part (saddle side) except for the backrest, and as part of the SMRT-MALL project, the travel guide LED display installed at the top of the door in the room has been replaced with LCD monitors.

In addition, the broadcasting device has been replaced with an integrated set-up, and the side route post has not been operated for a while due to the installation of the screen door (PSD), followed by the removal of the side information post and Wi-Fi terminals (SK Telecom, KT, and LG U+).