Customizable TPU grommet. Useful when you need to make a hole in a solid surface (e.g. wall, desk) for running cables through, but want it to look nicer than a bare hole and don't want other stuff (bugs, weather, crumbs, etc) getting through. 

By default the flange settings will be applied to both ends, but that can be overridden if you need an asymmetrical grommet.

Generated grommet can be split in half along length or width to make printing easier and so you can actually squish the things into your hole. Default split is "hotdog" style which is the best for inserting into a hole in drywall without risking it coming out. "Hamburger" split may be better if you need to cap two sides of a hole separately and will anchor them another way or are content with a friction-fit. 

For “hotdog” split models, you can print in one of two ways. If your flange only sticks out by ~1mm, and the grommet is small enough that your printer can handle the bridge across the center, you can print in a vertical orientation with no supports and get a great result. 

If you have a larger flange, or use the customizer to add a hole down the center, you'll need to to print in a horizontal orientation to avoid supports. This will look a little messier on the inside, and may still require supports if you print a large one (depending on how steep the internal overhangs of the cylinder become). But any supports needed in this orientation will be easy to remove. 

You can use scissors/clippers/knife/whatever to make additional cuts in the ends to make it easier to run cables through it.

For most projects you'll want to print this in TPU or another flexible filament. 

Default settings will nicely plug a 3/4" dia hole that is 1/2" thick (e.g., in standard drywall).