52mm Aluminum Lens Reversal Filter Adapter Ring for Nikon AI

Pros: Its made of aluminium, very precise built, it fixes very well in my Nikkor 50mm f/1.8 filter thread and on the camera mount too.

Cons: Nothing i can find.

Other: Be careful to not let it drop on the floor cuz it coud damage the thread and do not put much strength when screwing the lens on it, if you for too much is gonna be hard to unscrew.
Coud have come with a case.

Pros: Good build, made of Aluminium, fits perfectly on the filter mount and on the camera body. Great for macro pictures, but you have to keep in mind that you have to adjust the settings manually if you want to actually see something in the pictures.

Cons: none that I can find

Other: I really recommend this product, it is far cheaper than buying a macro lens. However, you have to keep in mind that your lens might get dirty, since it was not designed to be reversed.