Canon BW-58C is the official and correct lens hood for the Canon New FD 35-70mm f/3.5-4.5 & 35-105mm f/3.5.4.5 GENUINE. Unlike standard screw-in hoods that match a filter thread (this one has 52mm filter size), the BW-58C uses a proprietary bayonet mount allowing it to be reversible for compact storage.