Schneider&reg; Topball 850 Green 0.5 mm Rollerball Refills - 2/pk you are buying TWO Schneider Topball green 0.5 mm line rollerball refills universal rollerball refills ink: green 0.5 mm line [Schneider defines as "medium"] bulk packaging Also available in a Four Color Pack [TB850-4ColorPack] as well as in an Assorted Color Ten Pack [850-Assorted]