My MBL Duo 4 TB originally had 2 x 2 TB Green AV drives. I have since changed that to 2 x 3 TB Red drives. Last I knew, the 8 TB MBLD had 4 TB Hitachi “Cool Spin” drives. At the time there were no WD Red or Green 4 TB drives. Those are available (Red) and probably will be soon for Green, so the innards of the large MBLD’s may change.
Because the MBLD is passively cooled, it really needs the low power consumption drives.