Pilot Hi-Tec-C Coleto Gel Ink Pen Refill 0.5mm, Black, &times; 6 Packs/total 6 pcs (Japan Import) [Komainu-Dou Original Package] Pen tip diameter: 0.5mm Line width: 0.25 mm Ink: Water biopolymer ink System: Slide lever type Ink Color: Black