Sturdy construction helmets are made of lightweight, molded nylon with a ratcheting headgear and moistureabsorbing headband lining. User can customized fit with a special up/down, forward/backward headband mechanism, reducing fatigue of the head and neck. Sensitivity adjustment knob is located outside the helmet making it more convenient to adjust. Upon striking an arc, the filter automatically changes from clear to dark in only 1/30,000 of a second. Four optical sensors for better dectection of the arc. Operator can set the delay time for the filter screen to change from dark to clear state - short, medium or long. Replacement lenses are available making changing scratched or damaged lenses fast and easy! Dual purpose welding or grinding mode. UV/IR Protection provide full protection for the user?s eyes and face, even in the light state at up to Shade 16 (DIN) at all times. Increased field of vision makes it easier to see the working parameter. Now measures 3.86? x 2.17?. Helmet is powered by high performance solar cells, and two built-in long lasting lithium-ion batteries. ADF lens conserves power by going to standby after 5 minutes of inactivity. Conforms with ANSI and CE safety standards.