The Pilot BLS-G1-5 Black Refill 0.5mm is a genuine Pilot gel pen refill designed for compatible Pilot G1 gel pens. Filled with rich black gel ink, it delivers exceptionally smooth, precise writing through its fine 0.5mm tip. Ideal for detailed writing, document preparation, note-taking, journaling, signatures, and everyday office or school use, this genuine Pilot refill restores your pen's original writing performance while extending its lifespan.