Anti-theft Faraday case for car keys / phone, 20cm x 11cm - Black The case protects electronic devices against mechanical damage, but also has a number of other functions. First of all, it blocks the signal, making the phone out of range, has an anti-radiation function and prevents demagnetization of data carriers and loss of files stored on them. Compatibility Due to its size, the case can not only accommodate keys or small data carriers, but also mobile phones with a maximum screen size of 6 inches. You can also fit GPS navigation, driving recorder, portable hard drive (provided it's the right size). Two way action Placing the mobile phone in the outer layer can reduce the radiation from the mobile phone part and has no effect on the connection of calls and text messages with the mobile phone; Putting the mobile phone in the inner layer and covering it to not only prevent electromagnetic radiation and protect people's health, but also to block the phone signal so that it is in "sleep" state. Then outsiders cannot get in touch with you. After placing the phone in the inner layer: If your mobile phone has not activated the call reminder function, a message will be displayed during the call that you are not available. If your mobile phone has the call reminder function enabled, when someone calls, they will hear that you are not available, and you will call back when you are free. When you have taken your phone out of the protective case, you will receive a text message reminding you to call. After placing the phone in the inner layer for about an hour, the phone will turn off if it does not receive a signal for an extended period of time. This applies to all standard devices - they start working when removed from the case. Specifications: Color: Black Size: 20 x 11 cm Suitable for: Smartphone, car keys, portable hard drive, GPS navigation, etc Compatible phone size: up to 6"