Nikon DK-18 Eyepiece Adapter for DG-2 To Use DG-2 with D-2 & D1 Series, F6, F5, F4s, F3HP, F100, N90 & N8008 Cameras
Canon Eyecup ED-E
This large eyecup keeps out most sunlight and other external light, sunstantial enhancing viewfinder visibility. It is especially helpful for eyeglass wearers when photographing outdoors. the mount can be rotated for vertical shots.