RAINBOW 170 HF RAINBOW 200 HF RAINBOW 170 HF and digital control RAINBOW 200 HF represents the latest evolution of inverter DC welding machines. These powerful 100 KHz power sources, based on the very latest IGBT technology and fitted with flat transformer, can be used for TIG welding of any metal, excluding aluminium and its alloys. RAINBOW 170 and 200 HF, which also perform very well in MMA welding , thanks to their light and compact size and excellent welding characteristics, are the ideal solution for maintenance, assembly and light fabrication works.