A disposable lens glued onto a micro four thirds camera body cap. It is fixed focus, with the focus starting around 1~2 meters. Of course, you can change that with a macro converter tube :-). The photographs below were taken with the adapted lens on a 10 and 16mm Meike macro extensions. I didn't (still don't, as of writing) have a proper macro lighting setup, so these were illuminated with a bright LED torch. You can see from the ISO used that this did much less than you would think! My cat was also pretty displeased with my shining a light on her when she was just trying to nap 😬.