If this was any more worthless, it would have a retched stench.  This card has completely turned me away from ever trusting another SanDisk product again.  I would only use this in the future to keep corrupt mis-information to frustrate anyone attempting to acquire any of my data.I have reformatted it 3-4 times IN FULL using various allocation sizes and operating systems.  It only functions under Windows, it randomly works in my mobile devices.  Now i'm left to decide if I want to bother researching this to better understand the problem in the future, or simply purchase another card from a more reliable manufacturer...... hello Kingston.