This is a fine example of a Cootie, or sideswiper, key. The premise is that you can move the lever to either side and make contact, but each side just closes the circuit in the same way a straight key does. Thus you need to construct the dits and dahs by hand on each side. I decided to challenge myself to learn to drive one properly, and am now comfortable to around 18wpm using it. Made by Tom G3HGE and very popular.