Canon Angle Finder B, attached to most F series (older F1, FT, FTb) and A series (AE-1, A1) cameras.
Allows eye-level viewing when the camera is in a vertical position, such as, on a copy stand or pointed down on a tripod.
This finder has a prism, which means the image is correctly oriented up and down and left-to-right. Like the Angle Finder A-2, it contains a built-in dioptric adjustment, rotates for horizontal or vertical use.  Ships via USPS Ground Advantage.