This is Shin Lim's Flash Deck Switch. The gimmick is the card case, and while there is some age-related deterioration typical of paper, I believe it is within an unnoticeable range. Additionally, parts are included so you can create your own with your favorite card case. The parts are also unused. The parts may have some age-related deterioration, but they are inexpensive items that can be obtained at 100-yen shops or magic shops. The explanation is online, with the URL written in the box.