Product description: 1.Max sound output:118±4dB 2.Sound gain: ≥32dB±2dB 3.Total harmonic wave distortion: ≤7% 4.Frequency range:300-4500MHz 5.Input Noise:≤32dB 6.Voltage:d.c.3.7V 7.Current:≤2mA 8. Full charging about 2-4 hours 9. Normal working about 35 hours
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