Sony A7R III (ILCE-7RM3) Eyecup Rubber Viewfinder Eyepiece Cover
Sony A7R (ILCE-7R), A7R IV ILCE-7RM4, A7 III (ILCE-7M3 / ILCE-7M3K), A9 II ILCE-9M2, A7R III (ILCE-7RM3). They also play an important role inpreventing any stray light from entering the viewfinder whilst you’re looking down it.