Specification: Item model number: ET-37 Product name: Clip-on Tuner Product features: 360° rotation small size simple operation Tuning mode: C twelve well-tempered / G guitar / B bass / V violin / U ukulele / W wind A4 reference audio frequency: 430Hz-450Hz Tuning range: A0(27.5Hz)-C8(4186Hz) Guitar falling accompaniment: b bb Wind music debugging: C F Bb Eb Battery: CR2032 Package including: 1 original box 3V button battery a manual a tuner machine