Auto-darkening Welding Helmet, self-tanning, polycarbonate electronic welder mask that changes from a light to dark state when welding activity begins. The light state is DIN4; The dark state is adjustable from DIN9 to DIN13 using the end button. The response time from light to dark state is 0.04 milliseconds; Returns from dark state to light state at 0.03-0.04 seconds. Energy is provided by solar cells with 2 built-in lithium batteries to provide power back up for a longer life. No need for replacement batteries. Adjustable 4-point harness with design for perfect fit; Solar cell batteries and lithium batteries increase working time to over 5,000 hours. Suitable for use with disposable respirators. Equipped with an LCD filter of superior optical quality suitable for: ARC, MIG, MAG (CO2), TIG welding, Plasma cutting, Grinding. Large viewing panel: 91mmx42mm; use for workshops, shipbuilding, metal industry, welding in maintenance, public works ... EN166 1 S, EN175 F, EN379 4 / 9-13; 1/1/1/2; EN 175: 1997; EN 379: 2009; ANSI/ISEA Z87.1: 2010;