TWSBI ECO Jade Fountain PenTWSBI Eco Jade Special Edition Fountain Pen features a clear acrylic body and light green cap. The Eco pen has a piston ink filling system, very smooth writing steel nib and a screw on cap. The TWSBI ECO 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. The Eco Pen cap has an inner cap to insure a perfect seal when stored away. TWSBI believes that it is