Jackson Safety Solera II Auto-Darkening Filters The auto-darkening filter (ADF) is a universal fit for most 2 inches x 4.25 inches welding helmets. Sleek, ultralight design at only 1.3 ounces will ensure maximum comfort. Solar powered. Compatible with HSL-1, HSL-2, and Huntsman series and many other brands of welding helmets. Pack of 1