This is a bung plug for a IBC tote.  It goes in the 6" cap of the IBC tote.  I couldn't get one with a vent in it or with the right threads for the inside of the IBC tote cap.  the center "vent pipe" is 1/2in outside diameter for a vent tube.  I have two IBC totes stacked on top of each other and are connected for water storage/use.  so the bottom tank needs to be vented to above the level of the top tank so they can act as "one big Tank".  So this Bung Plug makes it possible.  

I printed it out of PETG, with 5 bottom layers, 4 walls, and 25% infill.  Hopefully this will make it water tight.  If not, I'll spray with with a water proofing spray.  

I also modified an existing Bung Wrench to have a hole in the middle so you can tighten and loosen this plug.  I have that in another model.