In one embodiment, an apparatus includes a frame comprising a top wall, a bottom wall, and sides defining an opening for receiving a plurality of removable electronic modules, a guide slidably insertable into the frame to partition an upper or lower portion of the opening when inserted into the frame, wherein the guide comprises a first edge for slidable engagement with the top wall or the bottom wall, and a lead screw extending from an opening in the guide spaced from a front end of the guide, to a back end of the guide for connecting the guide to the frame.