The ID Duo is the pocket office for school, university and work and combines two functions in one pen: on the one side, the ink roller writes with royal blue ink and on the other, the highlighter marks with yellow luminous ink. The replaceable writing cartridge 852 has a wear resistant rollerball tip made of stainless steel. The blue ink is erasable and the script can be overwritten with the highlighter tip after it has dried. The 142 highlighting cartridge contains yellow luminous ink. With a line thickness of approx. 2 mm, the stable fibre tip is ideal for underlining and highlighting important parts of the text. Both cartridges are equipped with an ink regulator that ensures an even line at all times. The ink supply is visible through the transparent cover.