The reason I'm calling it rare is I researched this on the internet, and only found 1 throughout the whole internet, and it was not for sale, just a part of a gentleman's "MUSEUM OF CODE PRACTICE OSCILLATORS". I know nothing about how this actually works, however, if you take the handle and put it in hole in the side of the case to wind it up, the reel begins to turn, and continues until the spring winds down. The reel can be started or stopped with the speed control which is the Railroad emblem looking device in the lower right hand corner. It appears that one of the reels is missing on the left side of the PERFECTOGRAPH which is where the paper tape would have went. Pretty interesting piece. I believe this was a trainign device to teach people how to read Morse Code. What you see is what you are getting. The box measures about 11 wide 8 inches deep and 7 high. Pictures are the Main Part of the description. Please ask any questions Before Purchasing. Thank you for looking at my listing.