The existence of a German "Siemens" exploder, 1941 model, has been
reported in the Middle East. It is smaller, lighter, and more compact than the
1937 model. There is no indicator window to show if the main spring is fully
wound, but the exploder cannot be fired until the winding is complete. In the
carrying case is a neon tube which can be placed across the exploder terminal. On
firing, the tube will light up if the exploder is working properly.