A device comprising a main body and a sub-body that is rotatably supported on a side surface of the main body, wherein a bearing is located on either the main body or the sub-body and a shaft that engages with said bearing is located on the other unit, the shaft having an extension that extends into the main body or the sub-body that has the bearing and a connecting area that is formed throughout the lengths of the shaft and the extension; there is a notch that is connected to the connecting area around the circumference of the extension; and a flexible printed circuit board is placed such that it runs through the connecting area inside the shaft, exits the notch of the extension along its circumference and wraps around the extension.