A device is disclosed that can automatically remove lids from trays and place lids on trays. Further the device can sense the presence of a lid on a tray and can sense the dimensions of the tray. Based on the sensed dimensions of the tray, the device can select an appropriate sized lid to place on the tray. In one embodiment of the invention, a device holds a lid with a lid manipulator having lid holders. At least one end mechanism is attached to at least one end of the lid manipulator, and the end mechanism folds the lid flaps of an appropriate lid. Guided by the lid manipulator, lids are then positioned on the tray.