rOtring Tikky Graphic Finliner Fibre-Tip Technical Drawing Pen, 0.5 mm, 12-pack, (S0814770). Fibre-tip pen has free ink technology for a constant, consistent line and long life. Metal-jacketed fibre-tip nibs provide superior precision when drawing with straightedges or templates. Long-lasting pigmented ink is lightfast and water-resistant, with a unique deep black color. Not refillable. The clear ink-level window shows amount of ink left in the reservoir at any time. Limited warranty: guaranteed for 2 years from original purchase date against defects in materials or workmanship.