Rain Barrel Bung Plug for 35 and 55 gallon drums

We have about 15 rain barrels around the house, most are converted from the standard 55 gallon drums.  However, we don't need the bung plugs which are typically installed however we don't want debris or mosquitos to get in, but still need to get into the drums occasionally for cleaning.  These plugs snap into place and remove easily.  Print in black to prevent algae, there's a flower graphic on top.  We painted ours a terra cotta color to match the barrels.