Tested every 10 hard drives (5 colors), tested 8 in a row at a speed of 9 - 12 Mbps (USB 2). Ironically, of the 2 black drives, one tested consistently higher (11-18Mbps) and the other black drive significantly lower (0kb - 17kb - 100kb - 4mb). So, not sure what's going on there, but generally good enough for my purposes. I haven't had them long enough to determine durability and as the speed of the 2 black discs varies significantly I'm unsure on quality control. (I would probably give 5 stars if the 2 black disks matched the rest better.)
32GB SanDisk USB Flash Drive (SDCZ430-032G-A46)
78 Review
Titan Gray Samsung BAR Plus 256GB USB 3.1 Flash Drive (MUF-256BE4/AM) with Up to 400MB/s Transfer Speed
69 Review
Samsung BAR Plus 128GB USB 3.1 Flash Drive - 400MB/s - Champagne Silver (MUF-128BE3/AM)
65 Review
Kingston DataTraveler flash drive 100 G3 256 GB, 1 pc. black
74 Review
8TB Seagate Backup Plus Hub Desktop Hard Drive with Data Recovery Services
56 Review
2 TB External HDD Western Digital WD Elements Portable (WDBU), USB 3.0, black
84 Review
🔜 Seagate Backup Plus Slim STHN2000400 2TB Portable Hard Drive - Black: Your Reliable External Storage Solution
93 Review
🔌 Seagate Expansion 3TB Portable USB 3.0 External Hard Drive (STEA3000400) in Black
60 Review