Australian Air-Crew escape compass

This is a World-War II escape compass issued to Australian air crew. It consists of two brass plated buttons, one of which is magnetized, and the other of which has a pin soldered on the convex face. To use the compass, the crewman would remove the buttons from their uniform, hold the pinback button with the pin facing up, and then nest the magnetic button over the top of the pinback button. The pin rested in an indentation in the center of the concave face of the magnetic button. Three luminous dots on the convex face of the magnetic button allowed viewing at night.

This is also one of the most radioactive compasses I have. At over 100,000 CPM (clicks per minute) on my Black Cat Systems GM-10 geiger counter, it generates more than twice the radioactivity than the second most radioactive compass (A WW-II TG Night Marching compass from the UK).