This design pursues one of the ideals for mobile use: a card shape. It can be carried around smartly, by folding it into the user's notebook or business card case or sliding it into a suit pocket. With no buttons on the front and rear aluminum panels, this design both clearly expresses the card shape and prevents accidental use while carrying it around. This design aims for subtlety and presence in a compact device, through surface processing that utilizes the feel of the aluminum materials. Although the device is thin, it can be connected to a personal computer using a USB cable.