Smarter Tools ST-1S Welding Helmet Extreme lightweight shell design -Reduces neck tension and fatigue Large 3-3/4 in. x 1-3/4 in. lens-Higher visibility when welding Sensitivity Adjustment Control-Adjusts for different welding environments Side-mounted DIN adjustment-Selects shades from 9-13 Solar-powered design-Eliminates the hassle of changing batteries