Pilot Parallel Pen 2-Color Calligraphy Pen Set with Black and Assorted Colors Ink Refills, 2.4 mm Nib (90051) Pen set contains 2.4mm Parallel Pen (green cap and barrel), 2 ink cartridges (red and blue) Pen Set comes with 18 Refill Cartridges (6 Black, 12 Assorted) Two different ink colors can flow fro the same nib for a beautiful graduated effect Create beautiful calligraphy with vibrant blendable inks Can be blended with other Parallel Pen ink colors for a unique graduated effect