Awarded to commemorate the first successful testing of Pakistan’s nuclear weapons, the Chagai-I test, held in the Chagai Hills, Baluchistan, 28 May 1998. The actual test took place beneath the Koh Kambaran Mountain (shown on the medal) in the Ras Koh range in the Chagai Division of Baluchistan.
It is estimated that 735,000 of these medals have been awarded to both military and civilian personnel involved in the test.
There are numerous unofficial specimens struck by military tailors.
(And, for some time, there was confusion regarding the purpose of this medal.)