The NW-E405, E407, E505, and E507 are stylish Network Walkman models, compact yet functionally rich. Comparing music to liquid in a vessel, the designer came up with an image of a glass perfume bottle for these models. By adopting a two-layered structure, he was able to impart a sense of transparency to the design. The shape of the units was rounded to fit sleekly in the hand, and with seven color variations to choose from, the user will find it both comfortable and fun to wear one when walking around town. The units also make use of a jog shuttle control, which can be easily operated with one hand. In addition, the three-dimensional animated display, which uses organic electroluminescence, gives a sense of unity between the main unit and the user interface. The movement of the contents of the display gives the impression of being connected with the jog shuttles hand-controlled movements.