Each card shows a flag of the International Code in colour on the face, with the signal letter or number and the meaning of the signal flag on the reverse. The phonetic spelling of the letter is also shown, making the set doubly useful. Although no longer required by some yachting authorities, professional seamen and navies still need a knowledge of flag signals. There are over 50 nautical flashcards in this set. Presented in a clear plastic hard case.