Great macro rings for NEX. Two rings together can be used from focal length about 20 (APS-C matrix), but it's easier to use with telescopic lenses. Don't forget that you need to have a lot of light to take a good macro picture (at my photos you can see 1600 iso with minimum aperture value, that's for better example of course, but you will need to lower exposure and aperture too) You also can use macro rings with lens adapters to other systems.
Great item and shipping time is acceptable.