Yosoo&reg; Red Flaming Skull Solar Auto-Darkening Welding Helmet UV / IR Protection:Up to shade DIN16 at all time Light state:Shade DIN 3 (S777),Shade DIN 4 (S777a) Variable shade:From DIN 9 to DIN 12 (S777), From DIN 9 to DIN 13 (S777a) Light-dark:1/30000s(0.000033 sec)(-5 C, 0.0008 sec), b)Dark-light:0.25~0.08s (short-middle-long) Power supply: Solar cells, no battery change required, Power On/Off: Fully automatic