PENBBS-500 Press-Type Piston Filling Transparent Gradient Fountain Pen

Material: Transparent acrylic/resin body (gradient color scheme), chrome-plated metal clip and ring, stainless steel nib (F-nib with blade or M-nib optional), plastic feed and capillary ink supply system, built-in piston filling mechanism Uses: Fountain pen for daily writing, calligraphy practice, and journaling. The transparent body allows you to see the ink level and color. The piston filling design eliminates the need for an external ink cartridge. The large ink capacity is suitable for extended writing sessions. Suitable for students, office workers, and fountain pen enthusiasts. Functions: Press-type piston filling mechanism for easy operation; transparent body allows you to see the ink level and color; multiple nib options to suit different writing needs (F-nib with blade is suitable for Chinese calligraphy practice, M-nib is suitable for calligraphy sketching); large ink capacity reduces frequent filling; clip for easy portability. Working principle: The fountain pen relies on capillary action to supply ink. The capillary grooves inside the feed continuously guide the ink in the piston's ink reservoir to the nib. When writing, the slit in the nib slightly opens under the pressure of the paper, and the ink flows out along the slit to the iridium tip, forming a uniform ink mark on the paper. The press-type piston mechanism pushes the piston to expel air by pressing the end of the pen. After releasing, the piston returns to its original position, creating negative pressure to draw ink into the ink reservoir. The transparent resin body allows for a direct observation of the ink color and remaining amount. Two gradient color schemes (Mojito Green / Fantasy Purple Pink) satisfy different aesthetic preferences.