f(x) has finally revealed their CFs for the popular footwear company, K-Swiss. In these CFs, however, the girls model schoolbags with interchangeable covers. Check out the videos below! Sulli's CF: - Sulli accidentally stains her bag, and then resolves the problem by switching up the cover. Victoria's CF: - Fans can catch a glimpse of Victoria speaking in Chinese to her mother, as she complains that she doesn't want to go to school. At the mention of Sulli coming along with her, however, she brightens up and decides to go. Krystal's CF: - Krystal is seen primping in front of a mirror, as she holds up two options of various accessories she's thinking to don for the day. In the end, she decides to go with her interchangeable backpack, and brightly moves on. Luna's CF: - Luna brags about her new backpack, which Victoria finds out is the exact same bag as her's. Fretting over how they'll be compared, Victoria huffs and puffs as she hurriedly changes the bag's cover to make it seem less noticeable. Sulli and Krystal are seen overreacting hilariously to the situation, exclaiming "Oh no!" and "How can this be?" Thanks for all the tips!