Outdoor power plug cover.
Designed for a specific type of plug. (https://www.amazon.com/gp/product/B07F66Y9FP/ref=ox_sc_act_title_1?smid=A1Z2N3J08F8CZB&psc=1)
It might not work if you are not using the same model.
But fell free to change it!
[UPDATE: 04/06/2020]: "ONO_Cover (V2).STL" uploaded. I made just some small changes. Better fitting and rounded corners.
PLEASE: Consider posting a making, this helps a lot
Say thanks by giving a tip and help me continue to create and share.