The welding helmet mod. 421 can be used for all types of welding processes as of 5 amperes (MIG/MAG electrodes, TIG/WIG, plasma jet cutting and welding) except laser and gas welding. It is specially recommended for TIG welding as it is equipped with a special detector for this kind of welding. Filter size is 110 x 90 x 9 mm. Filter blackout is DIN 4 (open) and DIN 9 – 13 (when welding). The shutter speed is 0.4 ms and the shutter speed is 0.1 – 1 s. The operating temperature is from – 10 C to + 55 C. The weight of the whole mask is 0.528 kg and is made of high quality poly-amide. Number of light detectors: 4.The mask uses solar energy and rechargeable batteries. EN 379 EN 175