Comes in EF, F, M, B, Stub1.1 nib choices Piston Filler Fountain pen. Simply unscrew the end cap, dip into ink, screw back the end cap, and your done! Ready to write!! Pen cap has an inner cap to insure a perfect seal when stored away. ECO-T has a slightly more pronounced grip section; to help with learning correct writing posture for kids, new enthusiast, and anyone who likes a little bit more structure to the grip area. Cap and end cap also has a rotary triangular shape design.