2x Drop and 2x Exp


MapleStory Events : Return of the Explorers Event
Return of the Explorers Event (6/16/10 - 7/13/10)
Explorer’s Box Event (6/16/10 - 7/13/10)


More info inside the links.

EDIT : It seems that nexon is making this look nice to make it up for the crappy 5th anniversary events.