The string descriptors are used to make it easier for humans to identify the device (the computer uses VID/PID to identify the device). Strings in a string descriptor can use spaces and a length up to 255 bytes (since the length field in the string descriptor is a byte) which translates into 127 characters (because the string is UNICODE).
RE: string descriptors
The string descriptors are used to make it easier for humans to identify the device (the computer uses VID/PID to identify the device). Strings in a string descriptor can use spaces and a length up to 255 bytes (since the length field in the string descriptor is a byte) which translates into 127 characters (because the string is UNICODE).