AUDEW Pro Solar Auto Darkening Welding Helmet Arc Tig Mig Grind Mask Grinding Viewing Windows:92.5 x 42.5mm. Response Time:0.15ms~0.2ms. retention time:0.4ms~0.8ms. This product with low batter display,test function and replaced battery,lithium Battery Powered with Solar Backup.. 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.