... of Germany . 4.The response time:1/25000s. Facial Mask Of Auto-darkening (EH-407/EF9242)1. Model ... two lithium batteries be changed.10. Switching time of Facial Mask:a) Light to dark: 1/25,000s.b ... 12. Power on/off : Automatic.13. EH-4 Helmets Series Adapt to ADF: EF9040J, EF9040,EF9242,EF9646,EF9848.14. ... argon arc/arc welding/Gas welding.15. Colour of Facial Mask : blue,green,silver,black,yellow,red, And ...