www.safetyandhealthmagazine.com/articles/auto-darkening-welding-helmets-3

Auto-darkening welding helmets

January 25, 2011
The 2450 series of welding helmets features a continuously variable 9-13 shade control. Variable sensitivity and delay allows the user to adjust the time required to bring the helmet from a darkened to a lightened state. The helmets include an integrated grind control, which fixes the lens shade at 3.5 inches to allow use as a grinding shield.

Lincoln Electric