Welding Helmet; Large 3.86 X 2.17 Inch viewing area Automatically changes from a light to a dark state when 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 corrosion resistant and flame retardant Ultra high performance filters protects against UV And IR Special turnover headband mechanism allows for greater comfort and reduces fatigue Utilizes high performance solar cells w/ 2 replaceable CR2450 batteries as power back-up Complies with DIN, ISO, EN safety standards, ANSI Z87.1-2003 standards, and CSA Z94.3 - 07 standards Switching Time: Light to Dark 1/30000 of a second Panel contains four (4) light sensors