Review on EASTFUN Flash Memory Indicator Colors by Shane Miller

This is exactly what you expect. I bought them 2 times and tested several pieces from each batch. Pretty extensive testing (clean disk, reformat, fill with small files, erase, reformat, flash complete disk image, repeat several times). They all passed. They are not fast: when writing / reading an image, the average speed is 7 MB / s in writing and 20 MB / s in reading. But that doesn't bother me since I mostly use them as boot disks for embedded devices.