The Piece OF9 is the 12th mini album by SF9. It was released on January 9, 2023 with "Puzzle" serving as the album's title track. Members Youngbin and Inseong did not participate in the recording & promotion of this album duex to them being on hiatus for their military service since March of last year. This comeback is also their last with member Rowoon following his departure from the group on September 18, 2023. Includes photobook and cd.