The present invention provides a white biaxially oriented polyester film having a two-layer structure of layer Alayer B, wherein the layer A contains a polyester having a melting point of 240 C. The printing screen mainly comprises a plurality of printing units, wherein each of the printing units comprises a body and a protrusion structure. In another embodiment, a tool attachment may include a planar coupling portion and at least one material removal portion projecting outwardly from the plane of the coupling portion. An electrical plug is mounted to the housing and electrically connected to the control unit. Thus, the control signal controls the frequency of the light transmitted by the tunable optical filter. The device attributes specify at least one of a media type, device type, or password for the device.