1930’s Rolleiflex standard K2. Has rolleikin attached which allows it to use 35mm film. Instead of 120. Film transports as it should. Lenses look clean. Even comes with a hand written note with a helpful tip on installing the Rolleikin. Shutter speed and aperture are set by levers on each side of the taking lens. These readings are shown in a window just above the viewing lens. There is a little groove in the front of the camera to allow connection to a flash outlet. I would say this is a later addition. The last 2 photos show this. This camera is from my personal collection
eBay