Auto-Helm AH88 Series Helmets powers up by solar power, and reacts automatically when you weld in a 1/10000 second time frame. This helmet is very easy to use, you can adjust the shades that you need to use, protect your eyes, and will last for many years before replacing the solar battery. They weigh barely 1lb, so you will forget that its even on you. The wide viewing window lens is 90 x 40mm so you can see everything that you want to weld. You can use this helmet for welding with MIG, TIG, or ARC welders. Auto-Helm Helmet Darkens the Instant You Start Welding. It Adjusts from a Variable Dark Shade #9 to #13, & clears to a Light shade #4. Auto-darkening lens never needs batteries and charges with exposure to welding or sunlight (solar powered). Extra wide viewing area for better performance (extra lens available). Padded ratcheting headgear with sweatband and light weight composite body reduces user fatigue. Exceeds ANSI Z87 Standards and Protects user from UV & IR Radiation. Darkens in 1/10,000 of a second and best of all, it has a shade adjustment control inside the helmet where it won"t accidentally get knocked out of adjustment, which means no surprises.