Viewing Area: 3-7/8" x 1-11/16" Square Conformity With CE & ANSI Z87 Standards Light Shade: Shade 4, Dark Shade: Adjustable 9 to 13 Super Fast Darkening Speed: 1/25,000 Second, With Full Range UV/IR Protection up Charges With Exposure to Welding or Sunlight Battery Powered With Solar Assist For Long Life 5000hrs Utilizes High Performance Solar Cells With Built-in 3V Lithium Battery as Power Fully Adjustable Ratchet Head Gear, Solar Powered Auto-Darkening Filter Helmet