Patent ID: 8760881

Claim:
A plug-in unit comprising: a printed circuit board on which a connector is mounted, the printed circuit board including a first groove configured to position the printed circuit board in a first position in which the connector is exposed and a second groove configured to position the printed circuit board in a second position in which the connector is covered; and a cover in which the printed circuit board is accommodated, the cover including a link bar configured to fit into the first groove and the second groove such that when the plug-in unit is inserted into a housing, the link bar fits into the first groove, and when the plug-in unit is in a standalone state, the link bar fits into the second groove so that the cover covers the connector, the cover including a movement groove along which the printed circuit board slides to fit into the first groove and the second groove, a guide rail along which the link bar slides, and a card lever, wherein when the card lever is manipulated, the link bar slides along the guide rail in synchronization with the card lever and fits to the printed circuit board.