These large cartridges each hold up to 80ml of ink and stick out from the front of the printer. The kit comes with a hook that fits inside the door sensor to make the printer think that the door is closed! Set-up is fairly easy, but please do not buy if you are not prepared for a little inconvenience during the initial set-up! Such users are best buying our smaller refillables that fit inside the printer the same as ordinary cartridges. They have a sponge-less design to improve print output and avoid problems with air bubbles and streaky print quality.