It is indeed a true class 10 made in japan. Delivered exFAT formatted for a total of 64Gb or 58,5Go. The speed with USB 3.0 drive in CrystalDisk Mark are the following: 45.24Mb / s in sequential read and 14.96Mb / s in sequential write (new items tested) PS: the comment will put a day if the card is revealed improper under practical use.