This is a clearance plate for a sewing machine. It would be slipped under the presser foot, raising it up a little, so you can sew over a big bump, like the leg seam on a pair of Levis.

The little hole will hold a needle when you're replacing the needle, so it doesn't slip from your fingers, and fall into the machine's guts.

Google or Youtube search "sewing clearance plate" for more info. The video "How to Sew a Jeans Hem." offers a good demonstration.
Fast forward about 11 minutes in. /watch?v=ItyTDVA3xgg

Machine sewing is new to me. I copied the shape and thicknesses as best I could from photos, and from my machine's dimensions. I'm not sure if it can be improved. Suggestions are welcomed.

8 grams ABS, 20 minutes.

Both metric and SAE files are provided.