The Benro Master 170mm Filter Holder is our largest filter holder, an ideal holder solution for ultra-wide lenses without filter threads, such as the Canon 11-24mmf/4L USM lens. It accomodates lens combinations with angles-of-view of up to 110° - and is compatible with other ultra wide-angle lenses for most full-frame, APS-C, MFT and larger-format cameras. Once in place, the holder secures a circular polarizer as well as drop-in filters up to 170mm wide and 2mm thick.