Finepoint System pens feature durable nylon tips that stay sharp for consistent performance. Set contains 0.1mm, 0.3mm and 0.5mm tips with water-resistant and fade-resistant permanent black ink for marking plastic, glass, metal, cellophane, film and wood. All tips are made of tough plastic to prevent fraying, so every line is precise. The tips are fitted into long metal sleeves to allow drawing inside templates and alongside rulers. The barrel is lightweight, durable and equally balanced to reduce fatigue during intricate, precision drafting. Each pen has a rubber cushion grip for added comfort. Finepoint System pens are disposable and nonrefillable.