As many returns here, this key Transcend 64GB lasted only 3 months. Common use for files - or size, reading and writing were not very fast but consistent with what you would expect at this price (when she was 25). And when connected to a PC the blue LED that remains on, it turns on and off at regular intervals (such potentiometer, not flashing). The PC sees a connection but no ability (as if it were an empty memory card reader yet recognized by the PC). Transcend carrier offers troubleshooting software on their website, but it does not see either key only solution proposed by them (good point for answering anyway) back to the seller, farewell content ... A strongly discouraged given the number of defective copies.
