This is a housing built for the Raspberry Pi v2. It has a hole at the top to allow for a ribbon cable to be attached to the expansion pins on the board.

You'd need small self-tapping 2mm screws to close the box.
Print both parts with the outside (top and bottom) downwards on to the build plate.

NOTE: Your slicer should generate support for the screw countersink otherwise you'll have a little cleaning up to do after the print.