Pentel Refill Ink for EnerGel Liquid Gel Pen, 0.5mm, Needle Tip, Red Ink, Box of 12 (LRN5-B-12) Refill for EnerGel Liquid Gel Pen (BLN75) Quick-drying, super-smooth ink 0.5mm, metal tip writes medium lines Red Ink 12 refills per box