pecifications: Pocket Hearing aidMax Sound Output: 129��4 dBMax Sound Gain: 50dB �� 5dBHarmonic Wave Distortion: ��5%Frequency Range: 450~3500 hzInput Noise: ��30 dBBattery: 1 x AA battery (Not included) Working Voltage: dc1.5V Working Current: ��4mA Color: As the picture showsItem Size: 7.0 x 3.0 x 2.7cmPackage Size: 12 x 8.5 x 3.3cmNet Weight: 26g