Three 0.4 mm medium line gel ink roller ball pens. Cosmic colors add flair to light and dark paper. Stunning new ultra-bright colors write on light and dark paper. Smooth-flowing gel ink is waterproof, fadeproof and permanent. Acid-free formula will not affect pH level of paper. Durable stainless steel tip writes smooth, 0.4 mm medium lines. Perfect for memory books, greeting cards, invitations, and more.