A liquid crystal display element includes array and counter substrates provided opposite to each other. The fan impeller structure includes a hub and a flow guide body. One or more of the plurality of dummy components is modifiable to form a unique identifier for the interposer die. The slider is slidably held in the body and is pushed by insertion of the object to slidingly move. A step may be positioned in the vacuum zones to define an open vacuum zone having multiple depths. The portable computer may be adapted to receive a user input identifying a media selection and transmit a control signal to cause the storage of the media selection.