HSR-350x, alternatively called G7, KHST or NG-KTX, and later officially renamed Hanvit 350, is a South Korean experimental high-speed train. It was developed and built in a joint project of government research institutes, universities and private companies that started in 1996, which aimed to reduce import dependence in high-speed rail technology. New components developed for the HSR-350x included motors, electronics, and the carbody of passenger cars. Test runs were conducted between 2002 and 2008. The experimental train achieved the South Korean rail speed record of in 2004. The HSR-350x was the basis for Korail's KTX-II (KTX-Sancheon) commercial high-speed trains.

HSR-350x, alternatively called G7, KHST or NG-KTX, and later officially renamed Hanvit 350, is a South Korean experimental high-speed train. It was developed and built in a joint project of government research institutes, universities and private companies that started in 1996, which aimed to reduce import dependence in high-speed rail technology. New components developed for the HSR-350x included motors, electronics, and the carbody of passenger cars. Test runs were conducted between 2002 and 2008. The experimental train achieved the South Korean rail speed record of in 2004. The HSR-350x was the basis for Korail's KTX-II (KTX-Sancheon) commercial high-speed trains.