This spare or replacement lens cap is designed to fit the Canon EF 400mm f/2.8L IS III USM super-telephoto lens, protecting its front element from dirt, finger prints and accidental damage. The lens cap fits securely to ensure it stays in place, but is also easy to remove quickly when youre working under pressure. Its made from tough, durable plastic. Benefits Protects front element from dirt and accidental damage Tough, lightweight design Designed specifically to fit the EF 400mm f/2.8L IS III USM Easy to remove quickly when youre working under pressure What\'s in the box E-180E Lens cap Compatibility EF 400mm f/2.8L IS III USM EF 400mm f/2.8L IS II USM RF 400mm F2.8L IS USM RF 800mm F5.6L IS USM