Features: Chromatic tuner for guitar, bass, violin, and ukulele. Rechargeable battery with 10-hour use. High-contrast display with flexible clip. Auto power-off for longer battery life. Specifications: Tuning range: A0 (27.50Hz) ~ C8 (4186Hz) Detection method: Piezo (Clip) Reference pitch: 431Hz~449Hz Tuning precision: +/-1 cent Power: Built-in rechargeable Li Po battery Dimensions: 49mm x 26mm x 40mm (1.93” x 1.02” x 1.57”) Weight: 21g (0.74oz)