1 liter x 4 HP 950 951 950XL 951XL HP officejet pro 8100 8600 Pigment bulk inkt - buy right kind - premium pigment refill ink, 2 yr shelf time - 1 black , 1 cyan , 1 magenta, 1 yellow / 1 liter per bottle ( double cap ) - total yield : 360,000 pages ( 90,000 pages / 1000ml bottle )