Compatible
KX-FA92 Black Thermal Fax Ribbons compatible with:
KX-FPG 386, KX-FPG 377, KX-FPG 378, KX-FPG 379, KX-FPG 381, KX-FPG 391, KX-FPG 550, KX-FPG 6550
The use of compatible supplies does not void your printer warranty