This mini sound amplifier will offer you precise sound amplification. Very simple to operate, convenient for daily use and travel use. You will regain the pleasure of enjoying music, movies and TV programs with it. Come and have a try. Features: Comes with silicone earplugs, not easy to slip off, it will be very comfortable to wear for a long time. Reliable quality, made of user-friendly material, flexible, safe to wear without harming ear canal. Easy to operate, helping you regain the pleasure of enjoying music, movies and TV programs. Adjustable volume, you can turn up the volume from low to high to meet your need. Battery-powered, convenient for you to replace the battery, waterproof and portable, great for daily and travel. Specifications: Type: Hearing Aid Model: F-138D Quantity: 1PC, 1 Pair(Optional) Material: Silica Gel; ABS; Metal Color: Khaki Battery: AG3 Button Battery(Battery Included) Max Sound Output: 130dB 4dB Max Sound Gain: 38dB 5dB Harmonic Wave Distortion: 5% Frequency Range: 300~4000 Hz Input Noise: 30 dB Working Voltage: dc1.5V Working Current: 2.5mA Package Size: Approx. 5.5*4.5*1cm / 2.17*1.77*0.40in Package Weight: Approx. 8g / 0.28oz Package list: 1 * Hearing Aid 3 * Earplugs 1 * User Manual