Allows you to use smaller size filters on lenses with a larger diameter thread. The first number is the size that screws into the lens, the second number is the filter size. Step " Down" Rings May Cause Vignetting.
Reviewed by 1 customers
Needed to adapt a close up filter to my 24-85mm EF Lens for some light macro use. Worked like a charm! Cheap and came in fast . No gripes at all.