TWSBI Eco Fountain Pen - Clear / Transparent YellowTWSBI has changed the game! TWSBI Eco combines simplicity and elegance in this very contemporary fountain pen. By using a piston ink filling system, TWSBI has been able to create a fountain pen with very high ink capacity. What this means is that you no longer need ink cartridges or a converter just fill this high capacity fountain pen and away you go. Why use this pen? The nibs are fantastic, the styling amazing, you will be asked about it everywhere