This mechanical contraption was how folks learned Morse Code before there was tapes. It’s a wind up mechanism that turns stacked metal discs. The discs have bumps corresponding to dits and dashes. The “wings” sticking out under the disc stack cause the “reading” mechanism to shift up one notch to the next disc and eventually it drops down again. This allowed for some semblance of randomness.
The reading mechanism was nothing more than a switch to turn a buzzer on and off.