This is the exact size and shape of the original NES (Nintendo Entertainment System) cartridge dust covers. The walls are sized to print 2 shells thick on a Replicator 2. At 0.2mm layer height this takes ~2 hours 15 minutes to print.
NOTE: If you have trouble with your replicator creating a weak seam at the "zipper" try setting your "retractDistance" to "1.1".
In addition to an STL, I included an X3G file for the Replicator 2.