Fotasy EG Eyecup for Canon EOS-1D Mark III/IV, 1Ds Mark III and 7D Cameras (Black) It provide cushioning around the camera's eyepiece It is especially useful to eyeglass wearers Compatible with Canon Eyecup Eg Block out unwanted light from your viewfinder For Canon EOS-1D Mark III/IV, 1Ds Mark III, and 7D cameras.