The NiSi 67mm Adaptor for NiSi Close Up Lens Kit NC 58mm (Step Down 67-58mm) allows the use of the NiSi Close Up Lens Kit NC 58mm on macro lenses with 67mm filter thread including the Canon EF 100mm f/2.8L Macro IS USM. It features a lightweight, aluminum-alloy construction that has a corrosion-resistant, black anodized finish for durability.
When the 58mm close up lens is used with the Canon EF 100mm f/2.8L Macro IS USM it will give an approximate 2:1 magnification ratio.
The ring is a step down from 67mm to 58mm.