Which Generation a Drobo system model number DRO4D-D belongs to ?

Hello,

we need to repurpose an existing Drobo system which has model number DRO4D-D.

I am unsure, however, which Generation a Drobo system model number DRO4D-D belongs to in order to get the latest versions of Drobo Dashboard, firmware and Documentation.

Any help would be greatly appreciated.

Thanks and Regards,

Massimiliano