Optional bayonet lens hood for select NIKKOR lens - Nikon 85mm f/1.4G, and attaches to 77mm filter threads.
Helps to reduce stray light which can cause flare.
Use of specifically engineered Nikon lens hoods is highly recommended.
In less-than-ideal lighting conditions, the performance difference can be substantial. By reducing the amount of non-essential light falling onto the front lens element, lenses can better achieve their optimum optical performance, producing more saturated images.