These printers use the T-6000 cartridge:
Toshiba e STUDIO 520
Toshiba e STUDIO 520-52CPM
Toshiba e STUDIO 600
Toshiba e STUDIO 600-60CPM
Toshiba e STUDIO 720
Toshiba e STUDIO 720-72CPM
Toshiba e STUDIO 850
Toshiba e STUDIO 850-85CPM
Panasonic WORKiO DP-6540
Panasonic WORKiO DP-7240
Panasonic WORKiO DP-8540