ET-155 Lens Hood
Fits to the front of the EF 800mm f/5.6L IS USM lens, reducing 'flare' caused by light shining directly on the lens' front element.
Canon 2705A001, 5.2 cm, White
Canon 2705A001. Compatible lens diameter: 5.2 cm, Product colour: White, Compatibility: EF400mm F2.8L IS USM, EF800mm F5.6L IS USM