The FDA-EP19 Eyepiece Cup from Sony is a replacement eyepiece cup for the camera's electronic viewfinder, compatible with the Sony a7 IV, a7S III, and a1 (Alpha 1). The soft touch eyepiece cup helps to protect your viewfinder from dust, moisture, and scratches. It allows more comfortable viewing when camera is held to eye, especially when wearing glasses. The design also helps to block out unwanted light, providing more detail while looking through the viewfinder.