LOVE love love my drobo, but maxing out my 4 drive unit (has latest firmware).
I am upgrading to 8 bay unit and selling the 4 bay.
Bottom serial number plate reads model DRO4D-D
Seems to identical to website description Drobo
Has firwewire and USB connectors at back.
Selling unit without drives for $200 ($269 new).
Can take latest 1 and 2tb drives.
S&H US $10.