DEC StorageWorks TZ89N-VW SBB
This is a DLT7000 (TZ89) DLT drive in a 5.25" StorageWorks canister which takes up three slots in a StorageWorks shelf. The TZ89 stores 35GB on a CompacTape IV cartridge, or 70GB if you can achieve a 2:1 compression ratio for the data being stored. The drive itself is made by Quantum as DEC sold their tape and disk product lines in 1994.
The drive takes up three slots in a StorageWorks shelf. By default, it takes the SCSI ID of the middle of the three slots it occupies. There are DIP switches on the back of the drive which can be changed to manually set the SCSI ID if required. Setting SW-1/2/3/4 ON and SW-5/6/7/8 OFF selects automatic (shelf-assigned) SCSI ID.
The front of the drive sticks out quite a long way compared to normal StorageWorks SBBs. While this isn't a problem for pedestal or rack-mount drive shelves, it is a problem for the StorageWorks shelves integrated into certain AlphaServer and Prioris models. While you could slot the drive into something like an AlphaServer DS20 you wouldn't be able to close the door.
As indicated by its label, this is a Wide SCSI device so only usable on BA356 and DS-BA356 drive shelves.