Cokin 37-46mm Step Up Ring: Cokin 37-46mm Step Up Ring is lightweight rings which allow the user to use 37mm
threaded filters on lens with 46mm filter threads. It is constructed from
aluminum-alloy that has a corrosion-resistant, black anodized finish for
durability and long lasting. The thin frame size minimizes vignetting when
attached to a lens and the black finish of the ring limits the chance of
internal light reflections. This adaptor rings serve to accommodate filters,
close-up lenses and other attachments to lenses with different filter thread
sizes. It allows you to use larger size filters on lenses with a smaller
diameter thread. The first number is the size that screws into the
lenses
and the second number is the filter size. This step-up ring has side knurling
to provide a more textured grip when mounting or removing it from a lens.