Welders in the path of today’s solar eclipse might not need to do anything special to see the first total solar eclipse viewable to the U.S. mainland since 1979.

While NASA advises people to use handheld solar viewers or glasses equipped with special-purpose solar filters to view the eclipse, the agency notes that welding helmets with Shade 12 or higher protection also are safe options.

“If you have an old welder’s helmet around the house and are thinking of using it to view the sun, make sure you know the filter’s shade number,” NASA cautions on its website. “If it’s less than 12 (and it probably is), don’t even think about using it to look at the sun.”

Even though Shade 12 is too dark for most kinds of welding, many people find the sun too bright for viewing through a Shade 12 filter, according to NASA, and some find the sun too dim for viewing through a Shade 14 filter.

While a Shade 13 filter might be just right for viewing the eclipse, such filters “are uncommon and can be hard to find,” NASA says.