The Forney 55681 standard-duty auto-darkening welding helmet has variable shades # 9-13. This helmet has a 3.68" (93.47mm) x 1.43" (36.32mm) viewing area and two optical sensors. Equipped with an outside mounted shade selector knob, internal continuous variable delay (.01 - 1.0 seconds), variable sensitivity controls, low level battery indicator and shade range switch (DIN 5-9, or 9-13). UV/IR protection up to shade DIN 13 continuous. Light state shade DIN 4/ variable shade DIN 9 - DIN 13. Power supply is solar cells with battery assist. Forney Industries is one of America's longest operating family-owned metal working product companies. Founded in 1932, Forney offers more than 5,000 products for the hardware, automotive, farm & ranch and do-it-yourself markets. If you've got metal working questions, we've got answers. We're committed to your success regardless of location size or needs. Please contact our customer service team at 1.800.521.6038 or www. firstname.lastname@example.org. Switching time light to dark is 1/25,000 of a second after arc is struck. Constructed of a lightweight impact resistant nylon shell and is equipped with a geared headband mechanism. Meets related DIN, ISO and EN safety standards including ANSI Z87.1 safety standards. Claims for warranty must be made within 90 days of the date of purchase. Proof of purchase required. This warranty does not cover any product that has been subject to misuse, neglect, negligence or accident, or that has been used in any way contrary to the purpose intended.