The Mark 14 nuclear bomb was a 1950s strategic thermonuclear weapon, the first deployed solid-fuel hydrogen bomb. It was an experimental design, and only five units were produced in early 1954. It was tested in April 1954 during the Castle Union nuclear test and had a yield of 6.9 Mt. The bomb is often listed as the TX-14 or EC-14. It has also been referred to as the "Alarm Clock" device though it has nothing to do with the design by the same name proposed earlier by Edward Teller and known as the Sloika in the Soviet Union.