Lock Ring for Canon RF 100-300mm f/2.8 L IS USM lens.

A lock ring is included with every lens hood order if required by the lens hood.
Lock Ring for Canon RF 100-300mm f/2.8 L IS USM lens. Compatible with Zemlin Photo HZ-124 Series Hoods. Approximate weight: 20g. Order only as a replacement or if using a hood on multiple lenses.