Black Caviar WD1001FALS open case Vs closed unit?

WD Internal Drives Desktop & Mobile Drives
4

It didn’t state it was used, I mean to me it looked brand new in a box.

Of course I’m not any expert at this at all, just confused.

http://www.staples.com/Western-Digital-Caviar-Black-1TB-SATA-Desktop-Hard-Drive/product_918227