Pelikan 4001 GTP/5 Ink Cartridges for Fountain Pens contain an ink formula that was developed over 125 years ago. This bold color ink protects both fountain pen and nib and produces clear line definition with an even flow. Made in Germany, this ink cartridge is for use with Pelikan fountain pens and many other brands using ink cartridges. 1.4Ml of ink in each cartridge. Royal Blue, 5 pack.