HP 728 300ml Matte Black Designjet Ink Cartridge (F9J68A)
HP had transit the old SKU of this ink to new SKU, as below:
HP 728B 300ml Matte Black Designjet Ink Cartridge (3WX30A)
Suitable for HP Designjet:
T730 / T830 Series Printer
Users must upgrade their printer’s firmware to be able to use the new part numbers, otherwise the printer will not recognize them. Printers updated will continue to accept current supplies as well as the new ones (with and without B). Firmware can be found in this URL and only needs to be done once per printer: www.hp.com/go/designjet/firmwareupdate
For any inquires, please call HP Support Care Line: 1800-88-8588 for further assistance.