picture frame hook / hanger
A hook/ hanger for picture frames.
Just put it arround the back plate on the top of the frame and hook it to a nail.
Scale it for your needs. It is stable enough to hold a simple A4-frame in the default scale.
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/f6qLropW9YX