These printers use the KX-FA76 cartridge:
Panasonic KX-FL 501
Panasonic KX-FL 502
Panasonic KX-FL 503 CN
Panasonic KX-FL 521
Panasonic KX-FLB 750
Panasonic KX-FLB 751
Panasonic KX-FLB 756
Panasonic KX-FLM 551
Panasonic KX-FLM 751
Panasonic KX FLB 753
Panasonic KX FLB 755
Panasonic KX FLB 758
Panasonic KX FLM 753
Panasonic KX FLM 755
Panasonic Multifunction Fax KX-FL 501
Panasonic Multifunction Fax KX-FL 521
Panasonic Multifunction Fax KX-FLB 751
Panasonic Multifunction Fax KX-FLM 551