This is a small plug with a coffee bean motif for use in preventing leakage from the sipping hole of disposable coffee cups.
It can be attached to a key ring or kept in your pocket and then inserted into the sipping hole of the disposable lid when being carried to prevent the occasional spill caused by movement.
Technical
The part was printed using Proto-Pasta's Aromatic Coffee a HTPLA at 0.1mm layers.
Printed laying on the side as shown in the photo, a little support is required under the ring loop and the tapered plug.
Cleanup the supports on the bottom of the taper plug for a smooth surface.
It should fit the std disposable coffee cup lid but you may need to scale up slightly depending on your material to obtain a snug fit.