Spindle speed specs?

What is the spindle speed of the WD portable drives?  5400 or 7200RPM?  Why aren’t they specified on the website at all?  I feel that is important information.  :-/

The only thing that is important in an external drive would be usb interface because its the one your ysing to transfer files. Even if you have a wd black inside a passport the speed would be the same because your using it as an external drive.