This is a scribing tool. You can place a pencil through the hole and then scribe at 1/8" increments between 1/4 -1 inches. Great for carpentry, cabinet installing, construction, and general woodworking. I have included two print profiles: PLA and PETG. I measured a bunch of different pencils I had laying around and chose a hole size that worked the best. It's a nice snug fit for my pencils, but since not all pencils are the same, you may need to try different ones or reem out the hole if necessary.

I did not come up with this design. I have seen similar products for sale on Temu and Amazon I believe.