286817 Feature: Small and delicate， beat and tuning 2 in 1. Headset mono out， practice beats anytime and anywhere Tempo: 30-250BPM Color: White Size: About 56 x 30 x 20 mm A4 frequency range: 440HZ Tempo: 30-250BPM Beat range: 0/4， 1/4， 2/4， 3/4， 4/4， 5/4， 3/8， 4/8， 5/8， 6/8， 7/8， 8/8， 9/8 Power supply mode: 1 x Button battery CR2032 ( not included ) 1 x Metronome 1 x English user manual In original package