Glue-in hole grommets

The intended application of this was to provide clean wire pass-throughs in a piece of ¾" plywood that constitutes the deck of the amp rack in my modest car audio build. I wanted a clean install with good wire management, and with limited space, the best way to do this was on the back side of the plywood. 

My first design involved locking tabs, but plywood can vary in thickness enough to allow rattling (my biggest car audio pet peeve). I simplified the design to a “glue-in” type. I used Gorilla Glue and so far these have survived perfectly fine. Since they don't protrude past the back of the board, cable management is a breeze. 

Sizes:

I'm including my F360 file so you can tweak it to your needs.