The Mitsubishi Uni Jetstream 4&1 Multi-Function Pen is what happens when everyday practicality is given a quietly clever upgrade. Housing four ballpoint inks and a mechanical pencil in one streamlined barrel, it’s designed for people who like their writing tools efficient, dependable, and rather pleasant to use—now offered in newly released colour variants for a contemporary touch.

Powered by Uni’s celebrated Jetstream ink, this pen reduces writing resistance by up to 40% compared to conventional oil-based ballpoints. The result is an exceptionally smooth glide across the page, whether you write quickly, slowly, or with a firm hand. Fast writers and left-handers will especially appreciate the quick-drying performance, which helps keep pages neat and smudge-free.

The 0.5 mm ballpoint tips strike a fine balance between clarity and presence, producing crisp, dark lines thanks to a high-density pigment blend with roughly twice the density of standard inks. The matching 0.5 mm mechanical pencil adds welcome versatility for planning, sketching, or moments when graphite simply feels right. A spring-loaded tip combined with a twin-ball mechanism supports the low-viscosity ink while preventing leaks and backflow, ensuring consistent, reliable performance.

What Makes It Work So Well

• Exceptionally Smooth Writing: Ultra-low-friction Jetstream ink reduces drag by up to 40%.

• Crisp, Bold Lines: High-density ink produces clear, dark writing on any paper.

• Clean and Reliable Design: Quick-drying ink and a twin-ball mechanism minimise smudging and prevent leaks.

Details

• Ink: Oil-Based (Black, Red, Blue, Green)
  
• Ballpoint Pen Tip: 0.5 mm
  
• Mechanical Pencil: 0.5 mm
  
• Barrel Diameter: 13.7 mm
  
• Length: 147.6 mm
  
• Material: Oil-Based Ink
  
• Country of Origin: Japan