Signal Electric MFG. Co. R- 68 Price $5.20
This Signal Electric Company practice key was produced at a price to the consumer of $5.20. At this time I am not clear as to when and how many years this item was produced. I believe this to be the model R-68. When this item was made it came with a cover for the black round object(buzzer or clicker) at the bottom left in the picture at the left. As can be seen, the cover is missing from the specimen featured on this page.
The connectors are for headphones and a power source. Notice also the bronze colored metal plate. This has the manufacturers name on it as well as the Morse alphabet.