Feature: 1. [With Adjustable Volume] The knob type sound control is convenient for you to adjust the volume according to your needs. 2. [Practical Hearing Device] This hearing device is designed for old people or people with hearing problems. 3. [With Silicone Earplugs] Silicone earplugs are soft and elastic, effectively relieving your ear discomfort. 4. [Easy to Hear the World] The hearing aid device has clear sound quality and big power can be used for compensation for hearing loss. 5. [Wear Comfortably] Easy to wear design, conform to your ear shape, stable wearing and can ensure comfort. Specification: Item Type: Hearing Amplifier Material: ABS Maximum Sound Output: 129+3dB Sound Gain: >= 40dB±5dB Total Harmonic Distortion: < 10% Frequency Range: 1000-4000MHz Input Noise: <32dB Current: <=1.2mA Built in Lithium Battery Capacity: 25mAh (included). Package List: 1 x Storage Box3 x Earplug1 x Brush1 x Hearing Amplifier 1 x Charging Cable1 x Manual