Fangrui Product Details 1. Made Of Hollow Rubber, It Can Be Touched Softly Even When Wearing Eyes. 2. Provide A Cushioning Effect Around The Viewfinder,especially Suitable For Users Wearing Glasses. 3. The Eyecup Is Mainly Used To Prevent Light From Entering The Eyecup During Long-term B-bulb Exposure.it Is An Essential Small Part For Taking Pictures. 4. It Can Prevent The Eyecup From Being Scratched When The Camera Is Not In Use;it Can Prevent Debris From Entering The Viewfinder When The Camera Is Stored. 5. How To Use:install It On The Outside Of The Eyepiece To Prevent Stray Light From Entering And Facilitate Clear Framing.when Using,first Remove The Rubber Eye Cup,and Then Insert The Eyecup Into The External Card Slot Of The Viewfinder. Function:protect Eyes And Viewfinder,make The World Of Slr Clearer Applicable Models:for Cameras With 18mm Aperture Eos 5d 20d 30d 10d Eos D60 Eos 66,eos 300,eos D30,eos 10,eos 300v,eos 88,eos 100,eos500,eos500n,eos 700,eos 750,eos 850,eos 1000n,eos 1000fn Colour:black Material:rubber Pack