The sandisk ultra fit™ usb 3.1 flash drive delivers performance that lets you move a full-length movie up to 15x faster than with standard usb 2.0 drives. 1 plus, thanks to its compact, streamlined design, you can plug it in and leave it in.. I have been using my cruzer fine for a few months now with my mac computer and today all of a sudden it went read only... i dont know what i did or if it just need something. please help me luz. The sandisk ultra fit usb 3.1 flash drive delivers performance that lets you move a full-length movie up to 15x faster than with standard usb 2.0 drives. plus, thanks to its compact, streamlined design, you can plug it in and leave it in..