Inksky CISS CIS Continuous ink system FOR HP cartridge HP 920BLACK/CYAN/MAGENTA/YELLOW 4PCS FOR HP Printer models:Officejet 6000 6000A 6500 6500A 7000 7000A 7500 7500A Manufactured in ISO 9001:2000 certified factory means you get a high quality product! HIGH QUALITY & LOW COST reduces printing costs up to 90%! ENVIRONMENTALLY FRIENDLY! Doesn't waste cartridges! THOUSANDS OF SATASIFIED CUSTOMERS SERVED! SEE OUR FEEDBACK! *Remember to REFILL the ink tanks before the actual ink levels drop below 20%. Prepare for this by having extra ink on hand! *PLEASE CONTACT US if you have any questions or concerns regarding installation so we can happily assist you. Seemingly large issues may be a quick, simple fix away!