We had originally printed this Morse Code key to operate in "Cootie" mode. You can read about that here. It turns out using a Cootie key is fun and easy on the wrist, but..... learning to operate a Cootie key does take some practice. That said, the automotive spark plug feeler gauge gave such an effortless feel we decided to make a small modification and create a Single Lever Paddle from the original design.
-----
This mod allows usage with an electronic keyer in three terminal mode. The two terminals on the left can be shorted to quickly switch into Cootie mode.
-----
-----