The Rolleikin's were an accessory that allows a TLR user to shoot 35mm film. This one comes with the leather case, but is missing the outer dial. It does have the viewfinder and focus screen masks and all the internal parts. Very often you'll see a camera with the outer dial from the Rolleikin still fitted. Maybe yours has one? I have never personally used one of these and am not sure which if not all models it fits.