This is a tiny part for a highly-specific purpose. Haoge makes a nice grip / L-bracket for the Olympus E-M5III camera -- but if you don't use the vertical leg of the L-bracket, you're left with a very sharp edge on the grip where it would have attached.

This is a plug that helps reduce the damage potential of the grip in this scenario. It fits in the remaining gap with a friction fit. Small notches are provided to help you remove the plug as needed.