A:AnswerIf the drive will fit in it, then it will work. I'm not sure if all external hard drives are of similar size or no, but it will work for a Western Digital 4 TB external hard drive.
A:AnswerI would not recommend enclosing an external harddrive (or SSD) in the case while backing up your laptop or any heavy use when you are transferring a lot of data to it. It will naturally get hot during this and enclosing it within a case will only make it hotter.
A:Answeri haven't tested it (intentionally or otherwise), but i don't think this case is waterproof...maybe water-resistant, but only in small quantities, such as a light spray or sprinkle, and even that is a very big maybe
A:AnswerNo, this case is for the smaller version of portable external hard drives such as the WD - My Passport for Mac 1TB External USB 3.0 Portable Hard Drive.