ND R@ 20OZ(5x4oz) refill ink kit with syringes for 901 901xl Black and Color ink cartridge:OfficeJet G510a G510g G510n J4524 J4540 J4550 J4580 J4624 J4660 Printers ND Brand refill ink for HP 901 901xl ink cartridge The item comes with detail refill instruction. You can refill ink for your original ink cartridge. It is a big saving. Highest UV resistant rating on market 5X4oz Black and Color ink The ink quality is same as OEM ink