High capacity and long-lasting, provide smooth writing and ink intensity. 0.5mm, black ink, quick-drying without smudge. The replacement ballpoint pen refill is compatible with many ballpoint pens, helping extend the life of your favorite expensive pen. 10 Pieces Gel Ink Pen Refills for retractable pens in the package, enough for your use and replacement in daily life, meeting your writing, study, and work demands. This retractable pen refill set can not only be applied as your own spare refill but also can be served as a gift for your family members, classmates, colleagues, and friends who have retractable pens; This must be a useful and thoughtful gift. Specifications: Name:10 Pieces Gel Ink Pen Refills  Material: plastic, ink Tip size: 0.5 mm Ink color: Black ink refill Package contents: 10 x Ballpoint pen refills replacement Features: Practical gifts: This retractable pen refill set can not only be applied as your own spare refills but also can be served as gifts for your family members, classmates, colleagues, and friends.  Widely applied: These ink refills for retractable pens are practical for home, office, school, factory, and so on, and can be applied for writing, drawing, sketching, etc.