The Canon ER-iE large eyecup is designed to prevent stray light from entering your viewfinder and causing glare. This is particularly useful if the photographer is wearing glasses, as it makes for more comfortable viewing. It can also prevent dust and moisture build up on your viewfinder as well, improving visibility. This eye cup is large, making it more comfortable and suitable for use in the brightest environments. Finally, the Canon ER-iE eyecup is compatible with EOS R1.BenefitsCompatible with EOS R1Prevents stray light from entering your viewfinder and causing glareProtects your viewfinder against dust, moisture and can resist minor impact and scratchesComfortable to the eye, and well suited to those who wear glassesLightweight and easy to secure to the cameraLarge eyecup has dimensions of 6.75 x 5.5 x 11.3mmThe Canon ER-iE large eyecup is designed to prevent stray light from entering your viewfinder and causing glare. This is particularly useful if the photographer is wearing gl