D`Addarios Nexxus 360 Rechargeable Guitar Tuning Head allows for fast and accurate tuning without the cost and hassle of changing batteries. The discreet clip-on design rotates 360 degrees and features an ultra-bright, full-color LED display to ensure perfect viewing angles and screen clarity in any lighting. When needed, simply plug the included USB cable into any USB device and enjoy 24 hours of tuning time on a single charge.