This issue is a variant of Adventure Comics (DC, 2009 series) #12 / 515 [Cover A].
Indicia reads: Adventure Comics #12/Adventure Comics #515 (Variant Cover).
Incentive cover shipped in 1:25 ratio to standard cover. "DC 75th Anniversary" variant cover. An homage to the cover of Legion of Super-Heroes, The (DC, 1980 series) #294. The Legionnaires are in costumes from various eras of Legion history.