Protects well
This case is made of soft silicone, and allows you to store a hard drive without too much fear of bumping it. It probably won't protect it from a fall, of course.
When you have several hard drives to store, these soft cases have interlocking feet, to stack them neatly.
As this case is soft and elastic, 5, 7 or 9mm hard drives fit in it without any problem.