Leica Chrome WINTU Right Angle Viewer for III Cameras [MINT-]
This is a fun little accessory that goes on the accessory shoe and lets you point the camera to the left while you look forward. It is great for stealth photography. It even has a little mirror so that you can use the rangefinder.
This one is in near mint condition nd works perfectly. The is clear but has a couple of specks near the center, which do not interfere with use.