"The Hobart Impact Variable-Shade Welding Helmet is a stylish, durable polyamide shell helmet that offers versatility with variable-shade lens darkening from 8-13. TIG capable, plus weld and grind modes. Meets ANSI Z87.1-2010 safety standards. Operates on CR2450 Lithium battery included. Switch time sec. 1/25,000, Adjustable Fit Ultra-comfort ratcheting headgear w/gel pad, Adjustable Sensitivity Yes, Auto Darkening Yes, UV/IR Coated Lens Yes, Variable Shades 8-13, light state #3, View Area W x H in. 3.82 x 1.81, Welding Processes Weld, TIG, grind mode, Product Type Welding helmet, Battery Included Yes, CSE/CE Standard CE, CSA, Low Battery Indicator Yes, Power Supply CR2450 lithium battery, ANSI Approved Yes. New Ultra-Comfort adjustable ratcheting headgear with gel pad provides an exceptional fit for all day comfort Convenient auto on/off Large 3.82in. x 1.81in. viewing area makes it easy to see what you're doing throughout the entire project Extra fast actual switching reaction time of 1/25,000 of a second 3 independent arc sensors for superb performance Low battery indicator provides early warning so you don't have to stop in the middle of a job Internally located controls provide easy sensitivity and delay adjustments Accepts magnifying cheater lens not included Includes extra pair of protective lens covers"