The product has a percussion rhythm speed function: TAP function, can accurately test your own heart beat speed or a song beat speed, has two-channel headphone output. Features: The back of the product has a clip and lanyard hole results designed to facilitate the fixed. Import sound unit, The beat sound is loud and the sound is nice. Adjustable volume control. Stereo earphone jack is available. Tap function enables you to test your ideal tempo or tempo of a track. Multi-functional and professional mini metronome is lightweight and portable, easy to use. Specifications: Color: yellow, blue, red, white, black (optional) Speed range: 30-280bpm The beat changes: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Accuracy: plus or minus 0.001 (thousandth) Volume adjustment: maximum volume, medium volume, minimum volume, mute Battery: 1 * CR2032, 3V, 240mAh (not included) Item size: 130 * 56 * 32mm / 5.1 * 2.2 * 1.3in Item weight: 23g / 0.8ounce Package size:130 * 80 * 40mm / 5.1 * 3.1 * 1.6in Package weight: 33g / 1.2ounce Package List: 1 * Metronome 1 * User Manual