EA and DICE have confirmed the four maps apart of the Battlefield 4 “Second Assault” add-on via a new trailer.

Operation Firestorm, Operation Metro, Caspian Border and Gulf of Oman will be headlining the upcoming DLC. All four maps have been reimagined and redesigned using Frostbite 3, putting the emphasis on destruction like you've never seen before with these maps.

Second Assault is the first of five Battlefield 4 expansions due for release by the summer of 2014, the others being December’s China Rising (available to those who pre-ordered the game), Naval Strike, Dragon's Teeth and Final Stand. Each add-on will come at no additional cost to those who’ve purchased a $50 Battlefield 4 Premium subscription.

Source: [Pixel Enemy — Youtube]