The idea behind the TWSBI Diamond 580 Clear fountain pen was to go back to basics and capture the simplicity and elegance of traditional writing instruments. The Diamond 580 is a classically styled fountain pen with a piston ink-filling system, smooth-writing steel nib and a screw-on cap. The traditional mechanism of the fountain pen, combined with a modern industrial design, embodies both the past and the present.

The TWSBI Diamond 580 piston ink-filling system uses only bottled ink and the clear body allows the user to view the level of ink remaining in the pen at all times.