This arrangement is for piano and D tin whistle (the most standard key of whistle that most players have).

You receive the tin whistle part without fingering diagrams, the same part but WITH fingering diagrams, the score, the separate piano part in case you need it, and a separate comprehensive fingering chart for your tin flute. So if you enjoy playing the notes on the staff, there is a part for you! And if you need the diagrams for learning, or for using every time, there's a part for you!