Boy am I embarassed
After following the link NatCh provided, I saw my Portable Vault drive on the Kaser website. I had wondered why people were describing this device as a mechanical drive. Kaser does too, and they make the drive. Maybe they know something. So I did an error-check on the drive and held it to my ear. Click click click. I think that is a major clue!
This is actually a 1.8" hard drive. It is very light, and quiet enough to fool me for two months! And to think I only paid $65 for it!