Use your own medium in this specially engineered pen. Dont be fooled by imitations The Kemper engineers designed this tool to give you a dripless, flawless, consistent width line that works with various mediums on anything. Each pen comes with stem cleaner to keep the minuet tip clear from particles or other debris. The specially engineered process does not allow for interchangeable tips, therefore, Kemper designed two pens This Fluid Writer Pen is for a medium or Large point line (See item # KFWPS for Fine point line) Fluid Writer is easy to use and easy to clean. Full instructions are provided with each pen