This step-down ring was exactly what I was looking for. I had purchased a fisheye adapter and needed the step-down ring in order to fit the adapter to some of my lenses. This ring provides a nice strong mount for my adapter. For the money, it can't be beat.
Well constructed and easily mated to the 52mm ring also sold by Adorama. Very good fit and finish and no binding or problems with adapting to a Nikon lens or to another adapter.