The Eyepiece is designed to seal out stray light for improved viewfinder optics. Made of soft TPU rubber, it protects your eyes from scratches, especially for eyeglass users. The eyepiece adopts an ergonomic oval shape to fit your eyes better. Besides, the eyepiece is 360º rotatable, so you can adjust it for horizontal or vertical view. 
JJC ES-A6300 Black Camera Eyecup Eye Cup Eyepiece Viewfinder For Sony Alpha a6300 / a6000 / NEX-6 / NEX-7 Replace Sony FDA-EP10