TWICEcoaster: Lane 2 is TWICE's 1st Special Album, released February 20, 2017 through JYP Entertainment, featuring lead single "Knock Knock." It comes in two versions — A and B — and serves as a companion to TWICEcoaster: Lane 1, compiling the earlier mini album's tracks alongside new additions for a 13-track total, with four CD-only bonus tracks including a TT remix and instrumentals. Each copy includes a 96-page photobook, sticker sheet, lyrics book, a photocard (1 random of 9), and a Knock Knock Goods item (1 random of 9), making the goods pull particularly fun for collectors. A pop-up store selling exclusive Lane 2 merchandise was held in Seoul during release week, adding to the era's collectibility.