Military Compass (1981)

This U.S. Army compass employs a tritium-containing radioluminescent compound. The latter, encased in glass, is positioned at the 12 o'clock mark on the glass cover, at the tip of the needle (1 o'clock in the photo to the right) and beneath the W and E markings. 

It was manufactured by Stocker and Yale Inc, of Beverly, Massachusetts. The Model designation, SandY 183, is derived from the company name.

As can be seen in the photo left, it originally contained 120 millicuries of tritium.