TWSBI ECO-T Saffron Fountain Pen (Medium Nib)The TWSBI ECO T fountain pen boasts an incredible value with its piston filling system and affordable price. This special edition features a crystal clear acrylic barrel so you can see your ink level, and a solid saffron orange yellow colored cap and piston knob. The pen cap has an inner cap to ensure a perfect seal when stored away. It is completed with silver trim and a silver stainless steel nib. The ECO T differs from the ECO in that it has a