This completely redesigned helmet is made of lightweight, molded nylon with a ratcheting headgear and moisture-absorbing lining on the headband. Designed and equipped with a special up/down, forward/backward headband mechanism, reducing fatigue of the head and neck. Every K-T auto darkening helmet now includes a magnifying lens holder as well as the actual lens itself. The sensitivity adjustment knob is located outside the helmet making it more convenient for the operator while at work. Adjust shade selection from 9 to 13 with the turn of a knob on the outside of the helmet. Shade guide table is provided for easy and accurate number selection. Upon striking an arc, the filter automatically changes from clear to dark in only 1/30,000 of a second. Operator sets the delay time for the filter screen to change from dark to clear state, short, medium or long. Changing scratched or damaged lenses is fast and easy. Clear outside lens and inside lens are available from K-T Industries. Set selection on outside of helmet for welding or grinding. Auto darkening filters provide full protection for the user's eyes and face, even in the light state. The UV/IR protection level is up to shade 16 (DIN) at all times. Conforms with ANSI and CE safety standards. Increased field of vision makes it easier to see the working parameter. It measure 3. 86 in x 2. 17 in. Each has four optical sensors. The helmet is powered by high-performance solar cells and has two built-in, 3 V Lithium batteries as power back-up. ADF lens turns off automatically after 5 min of inactivity to conserve power. Feature located on the inside of the helmet to test the batteries condition.