InkOwl Empty Refillable Cartridge Set for HP DesignJet T610, T620, T770, T790, T1100, T1120, T1200, T1300, T2300 (#72 cartridges) This cartridge pack allows you to save big by refilling your HP DesignJet printer. The cartridges have auto-reset chips, so you'll always have accurate ink levels. When a cartridge goes empty, remove it, refill it with the provided funnel, and when you put it back in, the printer will see it as full. Includes: 6 empty refillable ink cartridges for HP #72 from InkOwl (130ml capacity), easy instructions covering the whole process from start to finish For absolute best results, use only an ink formulation compatible and color-matched to the original HP 72 inks. InkOwl's compatible ink for HP 72-series printers is available on Amazon.