1x Mini In Ear Hearing Amplifier Sound Voice Amplifier Enhancer Both Ear Can Use

Specifications: 1.Sound Gain: 30dB ± 5dB 2.Voltage: DC 1.5V 3.Total harmonic wave distortion: ≤10% 4. Equivalent Input Noise: ≤40dB 5.Frequency Range: 300Hz ~ 4000Hz 6.Standard Battery: A10 7.Max sound output: 110 ± 5dB 8.