HOTCOLOR 4 Pack (BK C M Y) Replacement for HP 11 Printhead for Inkjet Pro k850 850dn Officejet 9110 9120 9130 1. What's in the box: 4 Pack -- ( Black Cyan Magenta Yellow ) 11 Print head [ C4810A C4811A C4812A C4813A ] 2. Compatible Printer: HP Business Inkjet 2800, 1000, 1100, 1200, 2300, 2600, cp1700. HP Designjet 10, 20, 50, 100, 120, 70, 100, 111, 500, 510, 800, 815, 820. HP Officejet 9110, 9120, 9130. HP Officejet Pro K850, K850dn. 3. Warm Tips: HOTCOLOR Remanufactured 11 printhead only work with 11 ink cartridges (To make professional results easy and reliable, providing an excellent value) 4. Guarantee: 120 days quality warranty.If there is any problem,DO NOT hesitate to contact us.