Lens is detached.	Screw-in mount inside the helicoid focusing lens mount.
Helicoid focusing lens mount is detached.

You can find the screw-in mount inside the helicoid focusing lens mount after detaching the lens. Other kinds of lenses can be attached here by means of the adapter.
When attaching the fast speed tele lens or bellows for close-ups, take off the helicoid forcusing lens mount first by depressing the helicoid focusing lens mount releasing button, and at the same time turning it counterclockwise. Then, attach them directly to the camera body.