Product Description A crucial component of a welding helmet, designed to protect the wearer's eyes from the harmful ultraviolet (UV) and infrared (IR) radiation emitted during welding processes. It typically has a variable-shade technology that automatically darkens to protect the eyes from the bright light of the welding arc. From the Manufacturer ArcOne S240-9 Horizontal Single Filter 2-Inch X 4 1/4-Inch X .2-Inch - Shade 9 is the most economical, general use auto-darkening filter. This is great for Stick, TIG and MIG welding applications between 50 and 300 amps. This filter is solar powered so there is never any batteries to change, and has an incredibly clear light state of 2.5. This filter features two independent sensors, 5.25 square inches of active viewing area and switching speed of 0.5 milliseconds. This filter is water and dust resistant, and is equipped with a dark to light delay of 0.2 seconds and up to shade 16 U/IR protection.