TWSBI Diamond 580 Iris Fountain Pen - Clear with plated aluminium trimCatching the light at the right angle The TWSBI Diamond 580 Iris Fountain Pen is a full size pen that uses an iridescent trim to catch the light and your eye. It shifts constantly as you move the pen, from blues, through to purples and pinks. Combined with the transparent demonstrator body, this pen feels part precision instrument and part moving object. A pen that reminds you writing is not a static task. Why youll love it Iris aluminium trim and nib