4 Walls is the fourth full-length studio album by South Korean girl group, F(x), released on October 27, 2015 by SM Entertainment. This is the group’s first release as four members since the departure of the member Sulli.
Track name: “Deja Vu’”
Work: Co-written by Dsign Music
Charts: #1 on US Billboard World Album Chart | #1 on Korean Gaon Charts