Rechargeable Hearing Aids Mini Digital Adjustable Tone In Ear Sound Amplifier Color: Black/White Frequency Range: 400-4000Hz Max OSPL90:=120dB ± 3dB Average OSPL90: =103dB ± 4dB Total Harmonic Wave Distortion: =7% Reference Test Gain: 23dB ±5dB EQ Input Noise: 29dB ±3dB Battery: Built-in Lithium Battery Features: 1.It looks like a bluetooth headset, which makes you feel more confident, you dont have to worry about discrimination anymore. 2.A Mini design Hearing aid for portability, invisible and convenient to carry. It makes you feel more comfortable. 3.USB rechargable, durable and reliable for long time(180 days) use. 4.It can greatly reduce noise, provide good sound quality. And help you hear the sound clearly and loudly, whether you are indoors or outdoors 5.The weight is less than 10 gram, SUPER light weight. 6.It just needs 1.5-2 hours to be fully charged,but it can be used for 10-16 hours in a quiet environment. Only 10 minutes of charging will have a 1.5 hours standby time. 7.Shockproof/Dropproof/user-friendly design,making it for a long time use 8.We have three different size of hearing aid earplug to choose from ,It will better fit your earhole and wont feel bloated and painful after you have wore it for a long time. Specifications: - Maximum OSPL90: ≦120±4dB - High frequency average OSPL90: 103dB±4dB - Total Harmonic Wave Distortion: ≤7% - Frequency range: 400-4000Hz - Input noise: ≦ 29DB±3 - Equivalent input noise level: ≦ 35dB - Total harmonic distortion:≦10% - Frequency response range:300Hz-3500Hz - Rated power supply current consumption:≦60mA - Work time : 10-12hours - Charging time:90min-2hours - Charging case working current:≦70mA - Charging case working voltage:3.7V - charging case charging time:90 min - Hearing aid charging current:≦30mA - Hearing aid charging voltage:4.2V - Hearing aid charging times(Double machine):3-4 times Package Included: 2 x Hearing aid 1 x Case 1 x USB Cable 6 x Earplug 1 x User Manual