This Large-View Auto-Darkening Welding Helmet with infinitely adjustable sensitivity and shade adjustment from #9 - #13. 0.0025 per second darkening feature with robust Li-Mi battery that charges with arc and solar power. Battery life is approximately 5000 welding hours. Viewing area is 3.6" x 2.6" and features replaceable lens protectors. Helmet has adjustable head band and features a very durable nylon constructed shell.