This is a twin pack of Original HP 650 Black Ink Advantage cartridges in retail blister packaging, so you get two black cartridges in a single purchase. HP 650 cartridges are the Ink Advantage line for HP's low-cost DeskJet Ink Advantage printers and all-in-ones, including the DeskJet Ink Advantage 2515 series that HP uses as its reference printer. The black ink is pigment-based for crisp, dark text and graphics that hold up over time. HP rates each HP 650 Black cartridge at approximately 360 pages at standard yield (tested in the DeskJet Ink Advantage 2515 All-in-One using ISO/IEC 24711 or HP methodology; actual yield varies), so the pack gives roughly 720 pages in total, a useful saving for households, students and small offices that print mostly black documents. Original HP cartridges are designed to prevent leaks and printhead damage, contain up to 70% recycled content, and are warranted to be free from defects in materials and workmanship. HP Planet Partners provides free cartridge recycling where available. Check your printer takes HP 650 cartridges before ordering; colour ink is not included.