Compatible Ink Cartridge Replacement for Dell 31 (Black, Yellow, Magenta, Cyan, 4-Pack) Dell 31 Black ink tank contains 35ml, Color ink tank contains 18ml. Compatible Printers: DELL V525w, DELL V725w Print Effectiveness: Make printing smoother, natural looking images and fewer granularities, producing best looking prints ever. Inks stop to come out automatically when printing is over. Technology: SPEED ink cartridges are adopted the leading Print Head Cleaning Technology, Print Head Testing Machine Technology, Eco Friendly Technology, Zero-energy Technology. The cartridges underwent an extensive process including, cleaning, testing the chip, ink vacuum refilling, totally pass to 27 production lines. All cartridges reach the standard when they are tested in any severe environment. Warranty: CE, TUV, ROHS, ISO9001, ISO4001 International Quality Certified.