.Rechargeable via USB Charging Cable: Our guitar tuner is built with a rechargeable battery inside, never needs a button battery replacement, and is very environmentally friendly too. Quickly charges with included USB cable on your PC or mobile power bank, and last over 10 hours of continuous use after a single charge The violin tuner saves energy with automatic Power-Down after 5 minutes of no signal. . Note Key Function: The clip on guitar tuner features a note key function which caters to the needs of most professional guitar players. When the device is in G(Guitar) tuning mode, short press this button to switch between the guitar tunings(DROP D,OPEN G,OPEN D,OPEN E) and flat tuning(b,bb). With this function there are more songs you can play. . High Sensitivity and Incredible Accuracy; Highly sensitive vibration-based tuning ensures your instrument is accurately tuned in a flash even with background noise. Not like other cheap tuners, this guitar tuner reads the low E string of bass guitar quickly and flawlessly without blipping on and off at all. . Compact Size and Large Screen: The ukulele tuner is almost frameless with a large LCD color display which makes it super easy to read even in a dark environment. With 360 degree rotatable clip, you can position the screen in any way you like. The tuner clamp is well engineered and small enough to fit right in your pocket or in the end of the guitar case.