The view window material of this helmet is partially transparent to visible light until an arc or similar light is struck. The shade darkness will drops from DIN4 to DIN 9-13 within 1 millisecond after the light is struck. Visible light transparency drops shall be adjustable by the helmets user among DIN 9-13 for different welding situations according to welding SHADE CHART.

The lens assembly always provides IR and UV protection to you at all time no power is required!