Rotring Isograph Pens are instruments created for engineers and architects, manufactured and designed with precision for optimum performance. Isograph pens offer Rotring's exclusive technology in select line widths in compliance with ISO standards. - Rotring Isograph Technical Pen College Set - 0.20mm, 0.30mm, 0.5mm, Set of 3Sanford Rotring Isogrph Pens, CLGPK .2/.3/.5MM - This set includes three Isograph pens (0.20 mm, 0.30 mm, and 0.50 mm), a Rotring Tikky 0.50 mm mechanical pencil, 12 hi-polymer HB leads, a B20 Rapid-Eraser, a 23 ml bottle of ink, and a compass attachment.