Variable shade #9-13 auto-darkening welding helmet with four optical sensors. Outside mounted shade selector knob and sensitivity adjustment. UV/IR (ultraviolet/infrared) protection: up to shade DIN 16 continuous. Light State: Shade DIN 4; Variable Shade: DIN 9 to DIN 13. Power Supply: High performance solar cells. Switching time light-to-dark: 1/30,000 of second after arc is struck; Switching time dark-to-light: 0.25 sec in "short" mode, 0.8 sec in "long" mode. Helmet has lightweight impact resistant nylon shell and is equipped with a geared headband mechanism that reduces the amount of head movement required to lower face shield just prior to welding. Meets related DIN/ISO (International Standards Organization) and EN (European Standard) Safety Standards and ANSI (American National Standards Institute) Z87.1 Safety Standards.