The Sony Lens Hood for 200-600mm is a dedicated bayonet-fit hood for the FE 200-600mm F5.6-6.3 G OSS lens. It helps keep stray light off the front element, which in turn reduces flare when you are working in bright, angled light. The hood also provides the lens with some physical shielding during day-to-day handling. It fits securely, turns smoothly into place, and is sized to match the 200-600mm lens.