OSIR 2 BK Replacement for HP 934XL 935XL Ink Cartridge with New Generation Chips High Yeild Compatible with HP Officejet Pro 6830 6835 6230 6812 6815 printers( 2 Pack) OSIR Ensure - Using high-quantity ink, the particles of ink is less than 20nm, which will print more fluently and give excellent color vibrancy for projects and everyday prints. Ink levels is NOT-OEM which will work as OEM capability. What is included - Hp 934XL/935XL Ink Cartridge( 2xBlack ) 2 Packs Approximate Page Yield - 1,500 Pages per Black and 725 Pages per Color (5% coverage) Printer Compatibility - HP OfficeJet Pro 6820 HP OfficeJet Pro 6830 OfficeJet Pro 6230 OfficeJet 6812 OfficeJet 6815 OfficeJet 6835 Printer. Certified Safe - With ISO9001 and MSDS Certificate Approved, we also provide 1-Year manufacturer 100% money back guarantee warranty. We believe in our cartridge, so we wont hesitate to make this commitment. You deserve it.