Versatile Welding Modes: AC Square Wave TIG, AC Pulse TIG, DC TIG, DC Pulse TIG, MMA, plus DC/Pulse/AC argon spot welding. Why you select our AIT200P AC/DC Tig Welder?. 【Pulse TIG Mode 】Minimal Distortion for Thin & Complex Workpieces Pulsed TIG balances strong penetration with drastically reduced heat input.