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 corrosion resistant 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 Complies with DIN, ISO, EN safety standards and ANSI Z87.1-2003 standards Replacement Lenses: Part #41264 Replacement Headgear: Part #41263 Switching Time: Light to Dark 1/30,000 of a second