The Miller Electric Dynasty 400 andMaxstar 400 deliver up to 400 amps of output power and exceptional TIG and stick welding performance. The Dynasty 400 is AC/DC TIG-stick-capable and welds up to 5/8" thick aluminum and steel in a single pass. The Maxstar 400 is DC TIG-stick-capable and welds up to 5/8" thick steel. Each stand-alone power source also includes the Cooler-on-Demand feature, which operates the auxiliary cooling system only when needed.