SPEED&trade; HP 21 21XL Black (C9351AN) Remanufactured Ink Cartridge for HP Deskjet Series Printer HP 21XL Black ink tank contains 20ml, yields up to 475 pages per cartridge @ 5% coverage. Compatible Printers: DeskJet D2430, DeskJet D2460, Deskjet 3930, Deskjet 3940, Deskjet D1320, Deskjet D1360, Deskjet D1420, Deskjet D2360, Deskjet F2110, Deskjet F2180, Deskjet F335, Deskjet F340, Deskjet F380, Deskjet F4135, Deskjet F4140, Deskjet F4180, Fax 1250, Fax 3180, Officejet 4315, Officejet J3640, Officejet J3680, PSC 1410. Print Effectiveness: Make printing smoother, natural looking images and fewer granularities, producing best looking prints ever. Inks stop to come out automatically when printing is over. Technology: SPEED ink cartridges are adopted the leading Print Head Cleaning Technology, Print Head Testing Machine Technology, Eco Friendly Technology, Zero-energy Technology. The cartridges underwent an extensive process including, cleaning, testing the chip, ink vacuum refilling, totally pass to 27 production lines. All cartridges reach the standard when they are tested in any severe environment. Warranty: CE, TUV, ROHS, ISO9001, ISO4001 International Quality Certified.