Here is a decription I found through 5 minutes of googling:
"This drive is a clean pull with 12 month warranty, the drive is new but has been taken out of a pre-built computer. This is often due to manufacturers like Acer, HP and Dell choosing to alter specifications of machines after production to follow consumer demand."
I still wouldn't trust a "clean pull" HDD. It means that someone other than the manufacturer has pulled the HDD out to sell it. Who knows how they handled it (touching bare hands on the PCB, throwing it around like a rag doll).