I want to apologise - I earlier posted about this (and similar) product. I was wrong - this is a 3.5" (wide) HDD - it's 5.5" long. That's what confused me. I think Digitec (wisely) moderated my post - the good censors!! I'm returning these for smaller 2.5" HDD but plan to stick with WD - decades of happy experiences with this brand. So, from personal experience - make sure you check all the dimensions before you buy.... Mea Culpa!