Independent arc sensors provide dependable arc detection. VSi™ features X-Mode and three independent arc sensors for unsurpassed arc detection. X-Mode prevents sunlight from darkening the lens before welding starts and low amperage lens opening from obstructed sensors. VSi and FS#10 2x4 Flip-Up feature integrated grinding shields. Provides impact protection and a clear view for grinding. Auto-on/off power control triggers lens at the strike of an arc.