The Kratt Master Key Pitch Pipe with Note Seletor circular pitch pipes cover the full range of the chromatic scale, using 13 hand-tuned special bronze reeds with patented tone chambers – precision tuned and checked to A-440. To assure proper note selection, scale is arranged in sequence and clearly marked by note notations on both top and bottom covers. The included master key note selector is the perfect accessory for the world-famous Master Key Pitch Instrument to assure finding the correct note under difficult conditions. Just blow into the note selector for the perfect pitch.