Faraday card sleeve – signal blocker for ID cards, 2pcsFeatures: The card sleeve works on the principle of a Faraday cage: like a shield, it blocks electromagnetic wavesThey do not send any signals themselves and do not affect other electrical devices outsideThanks to Michael Faraday’s discovery, many devices in our daily lives protect us from the harmful effects of waves or electrical discharges (such as cables, microwave ovens, cars, airplanes etc)These card sleeves are designed for ID cards to protect the information they contain from being read and from data degaussing from interference of electromagnetic fields If the bank card is placed in this shielding sleeve, the signal of the mobile phone can be prevented from degaussing the bank card, thereby avoiding the trouble of eliminating the tapeSpecifications: Dimensions: 88x57mmWeight: 3g x2Set includes 2pcsSignal blocking: RFID, Bluetooth, 4G connection, Wifi, GPS, GSM, etc