Taylor Guitars Digital Headstock Tuner. Clip-on chromatic guitar tuner picks up vibration and comes with a built-in mic. Back-lit LCD changes color to show correct tuning. Swivel design for easy viewing. Automatic power-off after 5 minutes. Quadra flat tuning for tuning with capo on. “A” calibration: 433-447 Hz with 1 Hz steps. Accuracy: ± 0.5 Cent. One coin cell battery included.