ArcPro 20704 Auto-Darkening Solar Powered Welding Helmet with Grinding Mode, Alien Design Extra-large 3.78-inch by 2.07-inch viewing field Shade DIN 9 to DIN 13 variable for welding; shade DIN 4 for grinding 1/25,000 second reaction time Stepless adjustable knob sensitivity control Automatic on/off switch with replaceable 3V Lithium batteries 3.78-inch x 2.07-inch viewing field Shade DIN 9 to DIN 13 Variable with Grinding Mode 1/25,000 sec. reaction time Permanent Shade DIN 16 for UV and IR protection. Automamtic on/off with replaceable lithium battery