This set includes parts to make any two of the following US nuclear bombs of the Mk 28 series; Mk 28EX, RE, IN, RI or FI. These bombs were carried externally by most US tactical fighters or internally by tactical or strategic bombers. The bomb lost at sea and subsequently recovered off Palomares in 1962 was a Mk 28RI, and CF-104s carried Mk 28EX or REs.