Solar Powered Auto Dark Welding Helmet Large 3.86 x 2.17 viewing area . Automatically changes from a light to a dark state as arc is struck . Variable shades from DIN 9 to DIN 13 . Outside sensitivity adjustments provide clear vision both prior and during welding . Durable, light weight material is and flame retardant . Ultra high performance filters protects against UV & IR . Special turnover headband mechanism allows for greater comfort and reduces fatigue . Utilizes high performance solar cells w/ 2 built-in 3V lithium batteries as power back-up . Switching Time: Light to Dark 1/30,000 of a second . Item UPC: 802090450051 45005 Prop65 information pending -