Replacement ink cartridges for Pilot V5 and V7 Cartridge System refillable rollerball pens. This pack contains 3 black ink cartridges. To replace the cartridge, hold the pen tip-up and pull the old cartridge off without twisting. Push the new cartridge on firmly to break the seal. Do not twist. These cartridges are not suitable for use in fountain pens. The V5 & V7 CARTRIDGE SYSTEM combines the smooth writing experience of the Hi-Tecpoint with the functionality and environmental responsibility of a refillable pen. This pack of 3 cartridges ensures your pen keeps writing.