[Product features] It is a case to prevent skimming and prevent magnetic data corruption. • Expansion of Skimming Damage Skimming damages have increased overseas, and damage is spreading even in Japan. In some cases, data may be extracted without touching the cards directly, and a tool to block radio waves is necessary. • [Magnetic damage troubleshooting measures] The number of people suffering from magnetic defects such as cards, passbooks, etc. has increased. In order to completely shield the magnet, special materials such as iron are required and it is not realistic as a case. Magnetism is weak in distance, and the method of taking distance from magnetism is effective. • [In case of magnetic damage troubles] In the case where it is too thin, the distance to the magnet becomes close, and the magnetism prevention effect can not be expected. This card case keeps the distance from the magnet away from the thickness of two layers of paper and aluminum. * Because it is not 100% magnetic shield, please do not bring it close to a powerful magnet. • [Size / number of sheets] Card case: 8.8 cm × 5.9 cm 5 pieces (insertion port: length) 8.9 cm × 5.7 cm 5 pieces (insertion port: sideways) passbook case: 14.8 cm × 9 cm 2 pieces (insertion port: Passport case: 14 cm × 9.7 cm 2 pieces (insertion port: sideways)