Using this D'Addario tuner is simple. First, use the lever - lock clamp to attach it securely to your violin or viola. Make sure the padded mount fits well on your instrument. Turn it on and you can start tuning. The full - color display will show you the tuning status clearly, even in the dark. When calibrating, you can adjust it within the 410 - 480Hz range according to your needs. As a practice tool, just play your instrument, and it will help you check your intonation. For maintenance, keep it in a dry place when not in use. Avoid dropping it as it may damage the internal piezo transducer. Also, clean the clamp and the screen gently with a soft cloth if they get dirty.