Beat frequency:20,40,60,80100,120,140,160,180,200 beats per minute,in 10 ranges,with an adjustable range.Power supply:220V/50Hz P13001, ELECTRONIC METRONOMEA timing instrument, with synchronous display of sound and light.Specification:Beat frequency: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200 beats per minute, in 10 ranges, with an adjustable range. Power supply: 220V/50Hz