FS... Water-based ink.... PFS... Permanent ink ITOYA's Finepoint System offers a variety of point sizes and two types of ink for all your writing needs. From everyday notes to labeling items to precision technical drawings, there's a Finepoint System pen for the job. Each Finepoint System pen features a rubber cushion grip for added comfort. Its lightweight, durable and equally balanced barrel makes everyday writing a breeze, and reduces fatigue during intricate, precision drafting. 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 Finepoint System pens are disposable, so there's no clogs, leaks or messy ink cartridges to deal with. The Finepoint System is available in two ink types and six tip diameters: 0.2mm, 0.4mm and 0.6mm tips with water-based black ink for paper and cardboard. 0.1mm, 0.3mm and 0.5mm tips with water and fade resistant permanent black ink for marking plastic, glass, metal, cellophane, film and wood.