Pentel Refill Ink, for EnerGel & Lancelot Gel Pen, 0.5mm Needle Tip, Fine, Blue Ink, Pack of 2 (LRN5BP2C) Refill for EnerGel Liquid Gel Pen (BLN75) Quick-drying, super-smooth ink 0.5mm, metal tip writes medium lines Blue Ink 2/Pk Carded