The Exakta RTL 1000 is a single-lens reflex camera, made in Germany circa 1970. Viewfinders are interchangeable, and this example is shown with the prism finder in place, and the waist-level finder alongside.
Some might consider this model the black sheep of the Exakta family, but I actually used this camera in 1979 as a 15-year-old novice and managed to get amazing results.