Newly manufactured ink tubes feature a universal design to replace three older part numbers (S4254, S6930U, S7605) to increase supply efficiency and storage for your Risograph digital duplicators or digital presses that handle print volumes too large for traditional office copiers. These F II Type ink tubes are compatible with Risograph EZ220, EZ221U, EZ590, EZ590U, EZ591U, MZ790, RZ200, RZ220, RZ220UI, RZ230, RZ310, RZ370, RZ390, RZ390UI, RZ590, RZ990, SF5130 EII U, SF5450 EIIU, SF9450. Genuine OEM smoothly delivers ink for exceptional output quality and consistent, brilliant color on every printed page. Inks dry quickly, preventing smudging. Risograph printer cartridges use emulsion inks formulated for stability. These inks won't suffer changes in viscosity that can affect print quality, even after they've sat on the shelf for a long time. Plug-and-play design makes them simple to install. Page yield varies with use.