Audew Solar Auto Darkening Welding Helmet Arc Tig mig certified mask grinding When arc is struck,Auto- darkening Filter will turn from clear state to dark state,response time is less than 1/1000S. Auto-Darkening welding Helmets are designed to protect the eyes and faces from spark, spatter, and harmful radiation under normal welding conditions. Lithium Battery Powered with Solar Backup,Ample mask space and very safe structure. Outside shade number and sensitivity adjustable can make the operators more convenient while operating. Auto darkening lens will automatically darkens to it's selected shade number when the light from welder is detected.