Review on Wolfgray 88XL Ink Cartridge Compatible For HP 88XL 88 XL Ink Cartridge For HP Officejet Pro K5400 K550 K8600 L7480 L7550 L7580 L7590 L7650 L7680 L7750 L7780 Printer(4Black) by Tim Knoepfle

Prints best in just (1 as a single, single, single) an hour. What a pity! Then a message is displayed that both (e.g. 2, Duo, Twin) printheads have a problem. This will disable the printer (HP L7680). Resetting doesn't help. It looks like the HP software recognized it as an alien element. Well, $18 wasted. I better order a double Blue London next time.