twin-lens reflex camera
A twin-lens reflex camera (TLR) is a type of camera with two objective lenses of the same focal length. One of the lenses is used to take the picture, while the other is used for the viewfinder system, which is usually viewed from above at waist level.
The best-known TLRs are those made under the Rolleiflex brand name by the German company Franke & Heidecke, later renamed Rollei, although the Rolleiflex brand was used for non-TLR cameras as well.