Description de chez Amazon USA : Performance Plus "Back to Basics" Pitch Pipes. The Performance Plus pitch pipe is a well-made tuning device to match the note you hear to the string tone you are adjusting. Performance Plus pitch pipes are designed for a lifetime of use with the proper care. Each has a Dark Royal Blue housing that is made of the highest quality ABS and surrounds the specially selected brass reed plate, developed for each type of instrument. Each vibrating note in the pitch pipe is created intensively by hand, shaping, tweaking and filing each individual brass reed note until perfect pitch is achieved. Each note is electronically tested for accuracy. A Pitch or Tuning Pipe is simple device for tuning an instrument the proper and original traditional way, "by ear" which helps develop a real sense of hearing and distinguishing the note pitch while tuning your instrument. Helps the student improve their ability to hear the note and match the pitch. Performance Plus pitch pipes come with a lifetime warranty and has sold one million pitch pipes. Performance Plus and is a leader in the school and student market. Please note: Do not blow too hard as a high velocity of air will distort the tone. It is best to lightly blow each note to produce a natural sound. There is a ridged lip that allows you to use the pitch pipe hands free by holding it in your lips. Performance Plus Pitch Pipes are made for most instruments: Steel String, Electric and Acoustic and Classical Guitars, 12 String and Bass Guitars, 4 and 5 String Banjos, Mandolins, Soprano Ukuleles, Violins, Cellos, Violas and Chromatic Pitch Pipes for Vocals and Choirs.