192-246  7207-012 1.2GB External 1/4" Tape Drive
192-009 7207-011  525MB External 1/4" Tape Drive
190-025 7207-001  150MB External 1/4" Tape Drive

7207-012:  Provides up to 1.2GB of data per cartridge and operates in streaming mode.  The 7207-012 has a sustained data transfer rate of 300 Kbytes/sec and can read tapes written in QIC-24 format and can read and write tapes in QIC-120, QIC-150, QIC-525, and QIC-1000 formats.

7207-011 offers four times greater reliability over the -001 by using new design technology breakthroughs. Provides over two times improvement in data transfer  rate over the 7207-001. (180KB/s! Wow!)

7207-001:
Capacity: Up to 150MB/cartridge (nominal), with ECC:  Up to 135MB/cartridge (nominal).
Compatibility:  6157 Model 1 (QIC-24) read only
                         6157 Model 2 (QIC-150) read/write
Data transfer rate:   90KB/sec.
Operation:            Streaming
Interface:            SCSI (single-ended) asynchronous