Welding Helmet ADF Controls Digital Battery Chemistry Lithium Ion Battery Life 2 000 hr Battery Type Disposable Cells Color Graphics EN379 Classification 1/1/1/3 Features Adjustable Sensitivity Auto-On/Off ClearLight(TM) Lens Technology Gen 1 Headgear Three Operating Modes Two Independent Arc Sensors Graphics Liberty Grind Mode Yes Head Diameter Maximum 25 1/2 in Head Diameter Minimum 21 1/2 in Helmet Material Nylon Helmet Type Auto-Darkening Helmet Width 8 in