[Gremlin]

The pair of adapters cost about twelve quids, there is no glass in them.
You need the pair because one of them had a catch to operate the aperture otherwise you need to hold it open with a match stick or rubber band
It manual focus only and you can change the shutter speed from the camera.
If you decide on one make sure you specify which camera you use and make sure you get a thread to fit the lens .