Who's This? Super-powered twin brothers on page 26 of Who's Who vol.XXIII.
How you could have heard of them: During Infinite Crisis, the brothers were subdued by the League of Assassins (in Villains United), then by Bane in Salvation Run, after which they are seemingly killed. New52 versions have appeared as members of the Ravagers, not that you're expected to have read that. They have also been featured on the Teen Titans animated series.
Example story: Teen Titans Spotlight #16 (1988) by Tony Isabella, Chuck Patton and Al Vey
With their element-based powers and the STAR Labs connection, I wonder if these guys might eventually be tapped for inclusion on the Flash series. Those seems key components...
Who else? Looking ahead, there's lots to do in the next volume of Who's Who, so we'll skip over Thunderbolt (had several series since the Charlton days) and the Time Commander (I discussed his appearances in Brave and the Bold on this very blog already). Volume 24, here I come!