Two small clips on the back secures the eyepiece onto your camera. Replaces CANON Eyecup EF. Custom designed soft-touch eyecup to provide cushioning around the camera's eyepiece. Block out unwanted light from your viewfinder. Useful for eyeglass wearers and others to keep the tip of the nose from touching the camera body. This eyecup is a replacement for Canon eyecup EF. It works a cushioning effect around the camera's eyepiece, which provides a protection for the camera's eyepiece. No matter you wear eyeglass or not, the hollow rubber of the eyecup is comfortable for your eyelid contact and your glasses. It impresses you a comfortable feeling. Compatibility: * Canon EOS REBEL XS XSI XT XTI T1I 500D 450D 400D 350D 300D