This is a refill pack to replenish the ink in our Continuous Ink Systems or our Refillable Cartridges. This refill pack holds 100ml of ink per color, which is equivalent to 8-10 cartridges PER COLOR! The bottles are EASY POUR, ensuring that the refill process is hassle free and fast. Both our Continuous Ink Systems and our Refillable Cartridges have "easy access" refill ports, so you do not need to be making holes - just open the bottles in this REFILL PACK, unscrew the tips, and pour ink directly into our Continuous Ink Systems refill ports (or via Syringe into our Refillable Cartridge refill ports). Fast, Easy, and best of all, an incredible value! The amount of ink in this purchase is equivalent to a total of around 50 cartridges worth of ink! If you had to buy each cartridge separately, you could spend over $600 for original cartridge brands, or over $300 for compatible cartridge brands. Using this refill pack on either our Continuous Ink Systems or our Refillable Cartridges yields you a net cost of under $3 per cartridge!