These printers use the ERC-41BK cartridge:

Epson ERC 41

Epson TM H-6000 III OptionAL ENDORSMENT PTR

Epson TM H-6000 IV OptionAL ENDORSEMENT

Epson TM H-6000 II

Epson TM H-6000 III

Epson TM-H 6000 ENDORSEMENT PTR

Epson TM-H 6000 II ENDORSEMENT PTR

Fujitsu DT 50 II ENDORSEMENT PTR