For use with the Fuji X100 Hood Bayonets to the Adapter Ring Adapter Ring replaces standard lens ring Adapter ring allows for use of 49mm filters This metal adapter ring replaces the lens ring that comes with the camera and bayonet mounts with the lens hood. In addition to bayoneting with the hood it can also be used for mounting 49mm filters. The metal lens hood helps minimize flare by providing shade to the optic. It also guards the lens against incidental bumps and abrasions. It also contains a slit that prevents it from blocking the viewfinder.