Using the D'Addario PW - CT - 21 NS Micro Clip - Free Tuner is a breeze. First, use the provided screws to attach the clip - free mount to your instrument's tuning machine. Once it's securely attached, turn on the tuner. It will pick up your instrument's vibrations through the built - in piezo transducer. Use the full - colour display to see the tuning status. You can select from four viewing angles to get the best view. When tuning in the dark, the tri - color reversible backlit LCD screen will help you see clearly. Remember, this tuner has a wide calibration range from 410Hz to 480Hz, so you can adjust it as needed. As for maintenance, keep it clean and dry. Avoid dropping it or exposing it to extreme temperatures. If you're not using it for a long time, turn it off to save battery life. This tuner can be used on many stringed instruments like guitars, basses, mandolins, and banjos, so enjoy tuning different instruments with it.