This is not an normal lens with a glass elements.
It's a plastic cone with a tiny metal disc, with a tiny hole inside.
It has a M4/3 mount.
This hole is the apprature, with the number F98/F128 (fixed).
So, a tripod is needed to take pictures with this lens.
I needed to do a lot of cleanup on my pictures, all the sensor  dust was visable on the pictures with this lens.
Not a lens for day to day shooting, put a nice lens to play with, if you'r interested in pinhole photography.