Fotodiox step-up rings are made with precision out of premium grade aluminum. Every ring is inspected to ensure smooth mounting and is polished and finished with anodized matte surface for professional appearance. Step up rings allow larger sized filters to fit on lenses with smaller sized filter threads. This step ring will allow the WonderPana145 filters with a 145mm thread to fit on lenses with a 82mm threaded front. Smaller step up rings can be used to adapt to smaller sized lenses (ie; if your lens has a 62mm filter thread, the 62-82mm and 82-145mm step up rings would be used together) and can be purchased separately.