B+W 26071 Filter Adapter Ring Black 52 to 37 mm

B+W - Adapter rings for adapting filters, auxiliary lenses and other attachments to lenses with different filter thread size As a rule, larger filters or attachments are adapted to smaller lens diameters in diameter. e.g. For photographic equipment that includes lenses with 52 and 49 mm filter threads, the use of 52 mm filters on both lens groups