Cord Pass Through

I wanted a simple grommet to pull my cables through a shelf I made for an invisible look. The I printed it upside down so I didn't have to use supports. The depth as installed is 18mm so it will fit 3/4" materials well. The inside dimension will fit a North American 2 prong plug and an HDMI connector but it is smaller than a 3 prong(NEMA 5-15) The actual dimensions are 25x40mm inside. I would recommend printing it and then using the part to mark the lines for cutting the hole but the hole dimensions will be 31x46mm if you want them.