I only wanted it for 48 hours, and I only had a physical card. When I arrived at the airport, the exchange store was already closed. The next day, I had to take a bus back to the airport to pick it up, and I also took care of my SES application. In 48 hours (three days), I visited N Seoul Tower, Hanboknam Bukchon Hanok Village Store, Sea Life Coex Aquarium, and Lotte World. Even though I went to Lotte World on a Friday, it was still very crowded. It took 1.5 hours to queue for just one ride, which was incredibly frustrating. I later found out that Korean children were on winter break. I highly recommend visiting the Sea Life Coex Aquarium; you can spend 1.5-2 hours there. I had originally planned to visit the Seoul Sky Observatory, but when I got there, I found out the ticket was only 10% off. I had researched it and then put it aside, not checking again before my trip, so I had to give up on that attraction and went to Lotte Mart instead.