The Vibrating Clip-On Digital Metronome is a fantastic small, compact, robust & easy-to-use accessory for musicians across the board, of all ages & ability level. Weighing just 30g & complete with 1x CR2032 watch battery included, this Digital Metronome is a fully functional accessory, packed full of superb features & easy-to-select options. With the option of keeping in time to either the flashing LED light, digital speaker beep, or built-in vibration, this superb, versatile Clip-On Metronome is the perfect choice for all musicians requiring a light, simple, easy-to-use Metronome for every day music performance use. Features: Available Beats: 0-9 Volume: Mute, Low, Medium, High Indication: Vibration, Speaker, LED Also used as a training aid for CPR when resuscitation is required after a cardiac arrest.