The IN500, Blank Input Plate Assembly is a Series 500 blank plate compatible with all Series 500 enclosures, such as the PS550. This board is inert - drawing no power from the system. Installation is quick and painless. UNPLUG THE POWER CORD ATTACHED TO THE ENCLOSURE. Simply remove the single mounting screw that holds the previous card. After removing the old input board, insert the new IN500 assembly. Replace the screw and reattach the power cord. The system automatically recognizes the removal of the old board so no further activity is required.