Mingus M50 Portable Mini Multi-functional Clip-On LCD Digital Beat Tempo Mini Metronome Come With Battery, Suitable for Piano, Violin, Guitar, Trap Drum - (Black) A multi-functional and professional mini metronome, lightweight portable, easy to use; Tap function enables you to test your ideal tempo or tempo of a track; Clip and lanyard hole designed, easy to carry and easy to fix; Stereo earphone jack is available. Power Supply: 1 x 3V Cell Battery (Included); Universal and suitable for piano, violin, guitar, trap drum, etc.