dearProfessional Metronome M50 Digital LCD Clip-on Tuner Metronomfor Guitar Piano Metronomo Musical Instrument Accessories 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: back of product has a clip and lanyard hole results designed to facilitate fixed. Import sound unit, beat sound is loud and sound is nice. Adjustable control. Stereo earphone jack is available. Tap function enables you to test your ideal tempo or tempo of a track. Multi-functional and professional metronome is lightweight and portable, easy to use. Specifications: Color: yellow, blue, red, white, black (optional) Speed : 30-280bpm beat changes: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Accuracy: plus or minus 0.001 (thousandth) adjustment: maximum , medium , minimum , 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