We've ordered this item several time before and it proved to be very reliable. This order we had 7 out of 100 did not work at all (error messages) when inserted into the computer. We tried on several computers at home and at the office. Nothing worked. They are defective. In addition to the 7 there were others that worked intermittently but we could save files to them. Definitely disappointed in this batch. Not sure we will place another order for this same item again. If we did not check each one, we would have embarrassed the company by handing out giveaways that did not work.