THESE LARGER REFILLABLE CARTRIDGES PROTRUDE FROM THE FRONT OF THE PRINTER OFFERING SEVERAL ADVANTAGES. THEY HOLD FAR MORE INK (80ML EACH), SIMILAR TO A CISS, BUT WITHOUT THE HASSLE OF THE TUBES. YOU CAN ALSO SEE HOW MUCH INK IS LEFT INSIDE OF THEM. THE DISADVANTAGE IS THAT YOU HAVE TO PUT A HOOK INSIDE THE DOOR SENSOR TO MAKE THE PRINTER THINK THAT THE INK DOOR IS CLOSED. ON MANY MODELS THE HOOK IS FIXED TO THE MAGENTA CARTRIDGE. ON A FEW OTHERS YOU WILL NEED TO PUT THE PLASTIC HOOK INSIDE THE SENSOR BY HAND. IF YOU DO NOT FEEL COMFORTABLE ABOUT DOING THIS THEN YOU ARE MAYBE BETTER BUYING THE SMALLER REFILLABLE CARTRIDGES THAT ALLOW YOU TO CLOSE THE DOOR.