The reduction ring is designed for a circular saw. The reduction to the saw blades allows the blade mounting hole to be reduced if it is larger than the saw shaft diameter. If you buy a blade that does not fit your saw, you must adjust it using the reduction ring shown. The reduction is made of steel with a ring thickness of 1 mm. Technical data Inner diameter (a): 16 mm Outer diameter (b): 20 mm Ring thickness: approx. 1mm https://elecena.pl/product/22622002/20-16-mm-reduction-ring-adapter-for-circular-saw-blades 2023-02-23 https://elecena.pl/product/22622002/20-16-mm-reduction-ring-adapter-for-circular-saw-blades 2025-10-28