rOtring Replacement Leads for Tikky Mechanical Pencils, 0.35 mm, Hard Black (HB) (S0312410) High-polymer fine leads from rOtring are flexible, strong, and easy to erase, providing a solid foundation for you to build on. Turn your mechanical pencil into something more than just a refillable pencil. Box includes 12 mechanical pencil lead refills. Limited warranty: guaranteed for 2 years from original purchase date against defects in materials or workmanship.