The product features a tap tempo function that allows you to accurately measure your heart rate or the beat speed of a song, with two-channel headphone output. Features: The back includes a clip and lanyard hole for easy attachment and secure carrying. High-quality sound unit produces clear and loud beats. Equipped with adjustable volume control. Stereo headphone jack included. Tap function helps determine the ideal tempo or track speed. Compact, lightweight, and portable metronome designed for easy operation. Specifications: Color: yellow, blue, red, white, black (available in options) Speed range: 30-280bpm Beat divisions: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Accuracy: ±0.001 Volume settings: maximum, medium, minimum, mute Battery: 1 * CR2032, 3V, 240mAh (battery not included) Item dimensions: 130 * 56 * 32mm / 5.1 * 2.2 * 1.3in Item weight: 23g / 0.8oz Package dimensions: 130 * 80 * 40mm / 5.1 * 3.1 * 1.6in Package weight: 33g / 1.2oz Package contents: 1 * Metronome 1 * User Manual