Experience the next generation of roller ball pen with the uni-ball Air. Featuring Smart Tip technology, the uniquely designed roller ball tip of the Air allows free flowing ink to glide smoothly across the paper for skip-free writing. With the capability for variable line widths according to pressure, Air adjusts to your writing style and gets better over time. The Air writes like a marker but with the durability of a roller ball for superior, smooth writing. 0.5mm Tungsten carbide ball, Plastic (PC/PP)barrel, Stainless Steel Tip. Superior, smooth writing experience, Scratch-free writing with a smooth glide. Variable line widths adjust to your writing style, Bold ink lay down. Writes soft like a marker but durable like a roller ball. Innovative Smart Tip technology writes at any angle.