BOSS TU-02 Clip-On Tuner - Color Display - For Guitar, Bass, Ukulele, etc. - Compact - 4 Tuning Modes - Up to 24 Hours Continuous Use - Auto Power Off Product Details Top Highlights Compact and accurate clip-on tuner Color display with excellent visibility 4 tuning modes (Chromatic / Guitar / Bass / Ukulele) Up to 24 hours of continuous use with a lithium button battery Auto power-off function to conserve battery when not in use *Please remove the paper from the back of the battery before turning on the power after opening. This item was purchased and only tested for a few minutes after opening.