• Liquid ink pens with uni-flow regulator system that ensures a constant and smooth ink flow until the last drop. • 0.7 mm stainless steel tip with tungsten carbide ball for smooth, medium-stroke writing. • High-quality Super Ink: an advanced pigment formula resistant to water, solvents, and fading. • Viewing window integrated into the pen body to easily monitor the remaining ink level. • Practical design with protective cap and metal clip for secure carrying in pockets or folders. • Case including 10 units in blue, ideal for intensive use in offices, study centers, or at home.