An insulator comprises at least three sections hingedly connected to one another, including a center section and a pair of outer sections. The method involves creating a tool having substantially the same surface dimensions of a product. The sidewalls partially cover upper surfaces of the battery cells. Each of the chessmen includes a second E-paper display unit for displaying a graphical data of a first chessman which corresponds to the graphical data of the first chessboard. The data masking power reduction module comprises logic configured to drive the DQ pins to a power saving state during a data masking operation. Top plates 110 are removably provided on a rubber toothed belt 120 by engagement members 111 provided on the back surfaces of the top plates 110, and engagement members 111 include sandwiching portions 112 which sandwich the toothed belt 120 from both outer sides in the width direction and terminate in pawl portions 113, which snap-connect the top plates to the toothed belt 120.