DEKO New Black Solar Auto Darkening Welding Helmet Welding Mask Adopt new technology,have high degree of protection,effectively block harmful light. You can adjust the degrees from the 6 to 13 according to your work requirement. Avoid the lens blur at low temperatures because of breathing ,and ensure breath normally. Sensitivity:lithium battery+solar cell(&gt;5000 welding hours) Welding Life Expectancy: 10 years High strong materials and fire retardant.