Uni-ball Air Pen - UBA 188 MUni ball Air Pen UBA 188 M The next generation of writing tools Experience the next generation of roller ball pen with the uni ball Air. 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 Tip : 0. 5mm